Irritable bowel syndrome: Difference between revisions

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In [[gastroenterology]], '''irritable bowel syndrome''' ('''IBS''') or '''spastic colon''' is a "a disorder with chronic or recurrent colonic symptoms without a clearcut etiology. This condition is characterized by chronic or recurrent abdominal pain, bloating, mucus in feces, and an erratic disturbance of defecation."<ref>{{MeSH}}</ref> IBS is fairly common and makes up 20–50% of visits to gastroenterologists. Lower [[abdominal]] pain, and bloating associated with alteration of bowel habits and abdominal discomfort relieved with [[defecation]] are the most frequent symptoms.
In some individuals, IBS may have an acute onset and develop after an [[infectious]] illness characterised by two or more of the following; [[fever]], [[vomiting]], [[acute]] [[diarrhoea]], positive stool culture. This post infective syndrome has consequently been termed "Post infectious IBS" ('''IBS-PI''') and is acute onset [[Rome Process|Rome II]] criteria positive. This condition is more homogenous, being mostly IBS-D and is drawing much clinical investigation.
Because of the name, IBS can be confused with [[inflammatory bowel disease]] (IBD), a more serious condition.
==Classification==
The abdominal pain type is usually described in a patient as either ''[[diarrhea]]-predominant'' ('''IBS-D'''), ''[[constipation]]-predominant'' ('''IBS-C''') or IBS with alternating stool pattern ('''IBS-A''').
==Symptoms==
The range of symptoms relating to IBS is relatively broad, but the main symptom is usually abdominal pain or discomfort associated with changes in bowel habits in the absence of any apparent structural abnormality. The pain is commonly relieved by [[defecating]] or modulated by other triggers of gut [[motility]].  Generally there is no pain when patients are asleep.  Symptoms usually start in young adulthood.
==Diagnosis==
In the past it was thought that the [[diagnosis]] of Irritable Bowel Syndrome relied on a diagnosis of exclusion.  That is, if one cannot find a cause then IBS is the diagnosis. Currently the diagnosis of Irritable Bowel Syndrome relies on meeting Rome II inclusion criteria (updated by Rome III criteria<ref name="FBD2006-Rome">Longstreth</ref>) and excluding other illnesses based on history, physical exam, and laboratory testing.  Although the Rome II and Rome III criteria were not designed to be a management guideline, it is currently a "gold standard" for the diagnosis of IBS.  Unfortunately an IBS diagnosis in an adult patient is still only useful as a tool to rule out more serious problems unless further investigation is employed to discern an addressable condition.
===Diagnostic criteria===
Several sets of diagnostic criteria have been proposed<ref name=pmid11570936>{{cite journal | author = Fass R, Longstreth G, Pimentel M, Fullerton S, Russak S, Chiou C, Reyes E, Crane P, Eisen G, McCarberg B, Ofman J | title = Evidence- and consensus-based practice guidelines for the diagnosis of irritable bowel syndrome. | journal = Arch Intern Med | volume = 161 | issue = 17 | pages = 2081-8 | year = 2001 | id = PMID 11570936}}</ref>. The importance of meeting diagnostic criteria it to reduce the possibility of underlying pathology. Significant underlying pathology is more common in referral setting<ref name="pmid6724251">{{cite journal |author=Kruis W, Thieme C, Weinzierl M, Schüssler P, Holl J, Paulus W |title=A diagnostic score for the irritable bowel syndrome. Its value in the exclusion of organic disease |journal=Gastroenterology |volume=87 |issue=1 |pages=1–7 |year=1984 |pmid=6724251 |doi=}}</ref> than in primary care<ref name="pmid2289644">{{cite journal |author=Bellentani S, Baldoni P, Petrella S, ''et al'' |title=A simple score for the identification of patients at high risk of organic diseases of the colon in the family doctor consulting room. The Local IBS Study Group |journal=Fam Pract |volume=7 |issue=4 |pages=307–12 |year=1990 |pmid=2289644 |doi=}}</ref>.
====Clinical History alone (Manning Criteria)====
In 1978 Manning et al. found <ref name=pmid698649>Manning AP, Thompson WG, Heaton KW, Morris AF. Towards positive diagnosis of the irritable bowel. ''BMJ'' 1978; '''2''': 653–4. PMID 698649</ref>, from questionnaire data, that IBS sufferers reported four common symptoms. The Manning Criteria was established to distinguish organic causes for symptoms from those of IBS. The Manning criteria, for the detection of organic gastrointestinal disease, have a sensitivity of 75% and specificity of 60% <ref name=pmid698649>Manning</ref><ref name=pmid2318433>{{cite journal | author = Talley N, Phillips S, Melton L, Mulvihill C, Wiltgen C, Zinsmeister A | title = Diagnostic value of the Manning criteria in irritable bowel syndrome. | journal = Gut | volume = 31 | issue = 1 | pages = 77-81 | year = 1990 | id = PMID 2318433}}</ref>. The prevalence of organic gastrointestinal disease (other than polyps or diverticulosis) among patients suspected of having irritable bowel is about 20% in a primary care clinic <ref name=pmid2289644>{{cite journal | author = Bellentani S, Baldoni P, Petrella S, Tata C, Armocida C, Marchegiano P, Saccoccio G, Manenti F | title = A simple score for the identification of patients at high risk of organic diseases of the colon in the family doctor consulting room. The Local IBS Study Group. | journal = Fam Pract | volume = 7 | issue = 4 | pages = 307-12 | year = 1990 | id = PMID 2289644}}</ref> and about 50% among patients referred to a gastroenterologist <ref name=pmid698649>Manning</ref><ref name=pmid2318433>Talley</ref><ref name=pmid6724251>{{cite journal | author = Kruis W, Thieme C, Weinzierl M, Schüssler P, Holl J, Paulus W | title = A diagnostic score for the irritable bowel syndrome. Its value in the exclusion of organic disease. | journal = Gastroenterology | volume = 87 | issue = 1 | pages = 1-7 | year = 1984 | id = PMID 6724251}}</ref><ref name=pmid1735330>{{cite journal | author = Frigerio G, Beretta A, Orsenigo G, Tadeo G, Imperiali G, Minoli G | title = Irritable bowel syndrome. Still far from a positive diagnosis. | journal = Dig Dis Sci | volume = 37 | issue = 2 | pages = 164-7 | year = 1992 | id = PMID 1735330}}</ref>. Thus, patients with less than 3 Manning criteria have about a 10% chance of organic gastrointestinal disease in primary care and 40% chance of in referral care.  In summary, the clinical history alone, as implemented by the Manning criteria, is not adequate to exclude underling organic illness.
====Clinical history and physical examination (Rome Criteria)====
In 1992 the [[Rome Process|Rome I Criteria]] were established by a multinational committee of specialists, which further refined the Manning Criteria. In 1998 the [[Rome Process|Rome Working Team]] proposed changes to the definition and diagnostic criteria for IBS to reflect new research data, and to improve clarity. These criteria have evolved, as the [[Rome Process]] has integrated fresh evidence and new conceptual approaches to the condition.
Physicians rely on a variety of procedures and laboratory tests to confirm a diagnosis. The cardinal requirement for the diagnosis of IBS is abdominal pain.  The [[Rome Process|Rome II Criteria]] is used to diagnose IBS after a careful examination of a sufferer's medical history and physical abdominal examination which looks for any 'red flag' symptoms. More recently, the [[Rome Process|Rome III criteria]], incorporating some changes over the previous set of criteria, have been issued. The [[Rome Process|Rome II and Rome III]] efforts have integrated [[pediatric]] contents to their set of criteria.
According to the [[Rome Process|Rome II committees]] and the [[Functional Brain Gut Research Group]],<ref name="FBD2000-Rome">Thompson WG, Longstreth GL, Drossman DA ''et al''. (2000). Functional Bowel Disorders. In: Drossman DA, Corazziari E, Talley NJ ''et al''. (eds.), ''Rome II: The Functional Gastrointestinal Disorders. Diagnosis, Pathophysiology and Treatment. A Multinational Consensus.'' Lawrence, KS: Allen Press. ISBN 0965683729.</ref>
IBS can be diagnosed based on at least 12 weeks, which need not be consecutive, of the preceding 12 months, there was abdominal discomfort or pain that had two out of three of these features:<ref name="IBSgroup2005-Criteria">[http://www.ibsgroup.org/main/diagnosis.shtml Irritable Bowel Syndrome Self Help and Support Group], (2005). Diagnostic Criteria. Retrieved on [[December 4]], [[2005]].</ref>
*Relieved with defecation; and/or
*Onset associated with a change in frequency of stool; and/or
*Onset associated with a change in form (appearance) of stool.
Symptoms that cumulatively support the diagnosis of IBS:
*Abnormal stool frequency (for research purposes, “abnormal” may be defined as greater than 3 bowel movements per day and less than 3 bowel movements per week);
*Abnormal stool form (lumpy/hard or loose/watery stool);
*Abnormal stool passage (straining, urgency, or feeling of incomplete evacuation);
*Passage of [[mucus]];
*Bloating or feeling of abdominal distention, which is some patients is measurable.<ref name="pmid17030170">{{cite journal |author=Houghton LA, Lea R, Agrawal A, Agrawal A, Reilly B, Whorwell PJ |title=Relationship of abdominal bloating to distention in irritable bowel syndrome and effect of bowel habit |journal=Gastroenterology |volume=131 |issue=4 |pages=1003–10 |year=2006 |pmid=17030170 |doi=10.1053/j.gastro.2006.07.015}}</ref>
Supportive symptoms of IBS:
:A) Fewer than three bowel movements a week
:B) More than three bowel movements a day
:C) Hard or lumpy stools
:D) Loose (mushy) or watery stools
:E) Straining during a bowel movement
:F) Urgency (having to rush to have a bowel movement)
:G) Feeling of incomplete bowel movement
:H) Passing mucus (white material) during a bowel movement
:I) Abdominal fullness, bloating, or swelling
''Diarrhea-predominant:'' At least 1 of B, D, F and none of A, C, E; or at least 2 of B, D, F and one of A or E. Hard or lumpy stools do not qualify.<br />
''Constipation-predominant:'' At least 1 of A, C, E and none of B, D, F; or at least 2 of A, C, E and one of B, D or F.
Red flag symptoms which are NOT typical of IBS:
*Pain that awakens/interferes with sleep
*Diarrhea that awakens/interferes with sleep
*Blood in the stool (visible or occult)
*Weight loss
*[[Fever]]
*Abnormal physical examination
An update to these criteria was issued at the [[Rome process|ROME III]] conference and published in May 2006.  <ref name="FBD2006-Rome">{{cite journal | author = Longstreth G, Thompson W, Chey W, Houghton L, Mearin F, Spiller R | title = Functional bowel disorders. | journal = Gastroenterology | volume = 130 | issue = 5 | pages = 1480-91 | year = 2006 | id = PMID 16678561}}</ref> The validity of subtypes is called into question:
:The validity and stability of such subtypes over time is unknown and should be the subject of future research.<br>
and
:Because of the characteristic symptom instability, we prefer the terms IBS with constipation and IBS with diarrhea instead of constipation- and diarrhea-predominant IBS. In this categorical system, many people whose features place them close to a subtype boundary change pattern without a major change in pathophysiology. Moreover, the heterogeneity and variable natural history of IBS significantly limit clinical trials of motility-active drugs and drug therapy in practice.
The sensitivity of the Rome criteria is probably inadequate to exclude organic disease without laboratory testing. The reader must be savvy to whether the sensitivity in a report is for the diagnosis of IBS or for he diagnosis of organic disease. In one study, the Rome criteria was reported to have a sensitivity of 100% and specificity of 65% (when used along with the absence of red flags) for the diagnosis of underlying ''organic'' gastrointestinal illness <ref name=pmid10520844>{{cite journal | author = Vanner S, Depew W, Paterson W, DaCosta L, Groll A, Simon J, Djurfeldt M | title = Predictive value of the Rome criteria for diagnosing the irritable bowel syndrome. | journal = Am J Gastroenterol | volume = 94 | issue = 10 | pages = 2912-7 | year = 1999 | doi = 10.1111/j.1572-0241.1999.01437.x | id = PMID 10520844}}</ref>. In this study, diagnostic accuracy for IBS is over 95% when Rome II criteria are met, history and physical exam do not suggest any other cause, and initial laboratory testing is negative <ref name=pmid10520844>Vanner</ref>.  However, this is a single study in a referral population and 91% of the patients already had negative imaging of their colon before the study. In a second study, Rome criteria for ''organic disease'' was 71% with a specificity of 85% <ref name=pmid12145798>{{cite journal | author = Tibble J, Sigthorsson G, Foster R, Forgacs I, Bjarnason I | title = Use of surrogate markers of inflammation and Rome criteria to distinguish organic from nonorganic intestinal disease. | journal = Gastroenterology | volume = 123 | issue = 2 | pages = 450-60 | year = 2002 | doi = 10.1053/gast.2002.34755 | id = PMID 12145798}}</ref>.
====Clinical history, physical examination, and basic laboratory tests (Kruis Criteria)====
The Kruis criteria include an ESR > 20 mm/2h, WBC > 10k and Hb < 12 g/dl (females) or <14 g/dl (males).
In addition to meeting these positive criteria patients have initial laboratory testing with a complete blood count, basic chemistry panel, and an erythrocyte sedimentation rate <ref name=pmid6724251>kruis</ref>.  Three studies of the Kruis criteria suggest the sensitivity is about 95% and specificity is 68% for diagnosing organic illness <ref name=pmid6724251>kruis</ref><ref name=pmid1735330>Frigerio</ref><ref name=pmid2289644>Bellentani</ref>. These values may be adequate to exclude organic disease in primary care, but cannot adequately exclude organic disease in referred patients.
===Differential diagnosis===
The diagnosis of a functional bowel disorder always presumes the absence of a structural or biochemical explanation for the symptoms. This can be excluded via:
*[[sigmoidoscopy]] or [[colonoscopy]]
*[[esophagogastroduodenoscopy]] (EGD, gastroscopy)
*abdominal [[medical ultrasonography|ultrasound]] or [[CT scan]]
*[[blood tests]]: [[complete blood count]], [[liver enzyme]]s, [[electrolyte]]s, [[renal function]], [[erythrocyte sedimentation rate]]
*stool chemistry (e.g. tests for [[exocrine pancreas insufficiency]] and other [[malabsorption]] conditions), stool [[microbiology]], [[fecal fat]]
*[[hydrogen|H<sub>2</sub>]]-tests for [[lactose intolerance]] and [[fructose malabsorption]]. However, the role of lactose is controversial <ref name=pmid7776987>{{cite journal | author = Suarez F, Savaiano D, Levitt M | title = A comparison of symptoms after the consumption of milk or lactose-hydrolyzed milk by people with self-reported severe lactose intolerance. | journal = N Engl J Med | volume = 333 | issue = 1 | pages = 1-4 | year = 1995 | id = PMID 7776987}}</ref>
*blood tests (immunoglobulin A anti-transglutaminase (tTG) antibodies and, if positive, then IgA antiendomysial antibodies (EMA)) or deep duodenal biopsy for [[celiac disease]].
**About 2% of patients (not necessarily patients with irritable bowel) who have one of: unexplained anemia, recurrent abdominal pain or bloating, abnormal liver enzymes, or previously diagnosed autoimmune disorder will have [[celiac disease]].<ref name="pmid17355413">{{cite journal |author=Catassi C, Kryszak D, Louis-Jacques O, ''et al'' |title=Detection of celiac disease in primary care: a multicenter case-finding study in north america |journal=Am. J. Gastroenterol. |volume=102 |issue=7 |pages=1454-60 |year=2007 |pmid=17355413 |doi=10.1111/j.1572-0241.2007.01173.x}}</ref>
Initial screening only requires a history and physical exam, as well as a [[full blood count]], [[electrolyte]]s, [[renal function]], and an [[erythrocyte sedimentation rate]].  Additional testing is done when there is a poor response to treatment.
While these modalities may be employed to rule out other causes of abdominal symptoms, they are not necessary to make a diagnosis of IBS. Depending on local practice, many doctors avoid overdiagnosing if the history is clearly suggestive of a functional bowel disorder.
Although few doctors will run a complete set of testing, when it is performed the underlying cause of their symptoms can often be found and treated.  Testing for [[bacteria]]l abnormalities, [[Food allergy|food allergies]] (IgG type allergies), and [[parasite]]s are particularly useful though often not covered by insurance and thus not performed.<!--
--><ref name="TheIrritableBowelSyndromeSolution2006-Wangen>Wangen, Stephen O. ''The Irritable Bowel Syndrome Solution''.  2006.  ISBN 0976853787. Excerpted with author's permission at [http://www.IBSTreatmentCenter.com/ The IBS Treatment Center]</ref>
===Diagnostic tests===
Researchers have demonstrated abnormal sensitivity in IBS patients to intestinal and esophageal distention with balloons.  However, this approach has not yet become available as a diagnostic test since the diagnostic accuracy is low and clinical utility is not yet high enough.
The diagnosis of IBS is made by exclusion as there are no serological (blood) markers.
A history of major life stress, anxiety, depression, abuse, or preceding infection may be suggestive, yet not diagnostic.  Organs outside the gastrointestinal system may be sources of referred symptoms, and abnormalities should be ruled out.
Red flags arguing against an IBS diagnosis include bleeding, weight loss, difficulty swallowing, nocturnal symptoms, incontinence, or onset of symptoms over the age of 50. Screening for ruling out colorectal cancer is still applicable.
==Pathophysiology==
IBS is highly prevalent in the Western world, but despite the advancement of many theories, no clear cause has yet been established. IBS may a conglomeration of disorders with similar symptoms but multiple different [[etiologies]] (root causes). As with many other medical conditions, there is a lot of speculation about causes, including in the field of [[alternative medicine]]. Increasing prevalence in developing countries suggests some possible links to diet and cultural factors.<ref name="NeurogastroenterolMoti2005-Gwee">Gwee KA. ''Irritable bowel syndrome in developing countries—a disorder of civilization or colonization?'' Neurogastroenterol Motil. 2005 Jun;17(3):317–24. PMID 15916618</ref>
===Genetics===
In [[twin study|studies of twins]], some <ref name=pmid11606493>{{cite journal | author = Levy R, Jones K, Whitehead W, Feld S, Talley N, Corey L | title = Irritable bowel syndrome in twins: heredity and social learning both contribute to etiology. | journal = Gastroenterology | volume = 121 | issue = 4 | pages = 799-804 | year = 2001 | id = PMID 11606493}}</ref><ref name=pmid17008364>{{cite journal | author = Bengtson MB, Ronning T, Vatn M, Harris J  | title = IBS in twins: genes and environment. | journal = Gut | volume = | issue = | pages = | year = 2006 | id = PMID 17008364}}</ref> but not all studies <ref name=pmid15929767>{{cite journal | author = Mohammed I, Cherkas L, Riley S, Spector T, Trudgill N | title = Genetic influences in irritable bowel syndrome: a twin study. | journal = Am J Gastroenterol | volume = 100 | issue = 6 | pages = 1340-4 | year = 2005 | id = PMID 15929767}}</ref>, a genetic role is found. In the two positive studies, IBS concordance in monozygotic twins is 17% - 22% compared to dizygotic twins having IBS concordance of 8% to 9%. In one of the studies further support for genetic influences being a minority contributor, a dizygotic twin with IBS has 15.2% IBS in mothers, compared to 6.7% in their co-twin<ref name=pmid11606493>Levy</ref>.
===Visceral hyperalgesia===
Evidence of visceral [[hyperalgesia]] (increased sensitivity to noxious stimuli in the gut) includes perception of pain from distention of a rectal balloon at smaller volumes than in normal patients <ref name=pmid16401465>{{cite journal | author = Lawal A, Kern M, Sidhu H, Hofmann C, Shaker R | title = Novel evidence for hypersensitivity of visceral sensory neural circuitry in irritable bowel syndrome patients. | journal = Gastroenterology | volume = 130 | issue = 1 | pages = 26-33 | year = 2006 | id = PMID 16401465}}</ref>.  However somatic sensitivity testing, such as in controlled pressure on the nails of the hand show that IBS patients have greater pain tolerance than normal patients. 
===Post-infectious or post-antibiotic===
Onset of IBS after an episodes of [[enteritis]] <ref name=pmid16928253>{{cite journal | author = Halvorson H, Schlett C, Riddle M | title = Postinfectious irritable bowel syndrome--a meta-analysis. | journal = Am J Gastroenterol | volume = 101 | issue = 8 | pages = 1894-9; quiz 1942 | year = 2006 | id = PMID 16928253}}</ref> or [[antibiotics]] <ref name=pmid11808932>{{cite journal | author = Maxwell P, Rink E, Kumar D, Mendall M | title = Antibiotics increase functional abdominal symptoms. | journal = Am J Gastroenterol | volume = 97 | issue = 1 | pages = 104-8 | year = 2002 | id = PMID 11808932}}</ref> have been described.  A [[meta-analysis]] found the prevalence of IBS to 9.8% after [[enteritis]] as compared to 1.2% in controls <ref name=pmid16928253>Halvorson</ref>. In these cases, a prolonged immune reaction may be the cause. Patients with IBS after a [[virus|viral]] illness may have a self limited course of only 3 to 6 months duration. A second meta-analysis reported "The odds of developing irritable bowel syndrome are increased sixfold after acute gastrointestinal infection. Young age, prolonged fever, anxiety and depression are risk factors for post-infectious irritable bowel syndrome". <ref name="pmid17661757">{{cite journal |author=Thabane M, Kottachchi DT, Marshall JK |title=Systematic review and meta-analysis: the incidence and prognosis of post-infectious irritable bowel syndrome |journal=Aliment. Pharmacol. Ther. |volume=26 |issue=4 |pages=535-44 |year=2007 |pmid=17661757 |doi=10.1111/j.1365-2036.2007.03399.x}}</ref> The role of premorbid psychological state affecting the outcome of organic illness has been described before.<ref name="pmid3230456">{{cite journal |author=Lane RS, Barsky AJ, Goodson JD |title=Discomfort and disability in upper respiratory tract infection |journal=Journal of general internal medicine : official journal of the Society for Research and Education in Primary Care Internal Medicine |volume=3 |issue=6 |pages=540-6 |year=1988 |pmid=3230456 |doi=}}PMID 3230456</ref>
===Food allergies and sensitivities===
Argument continues on the definition of cause as regards IBS and food allergies, but studies demonstrate that IBS symptoms are sometimes caused by immune response to foods and exclusion of those foods to which the immune system is responding results in reduction or elimination of IBS symptoms, a cause and effect link.<ref name="ScandJGastroenterol2005Jul40(7):800–7>{{cite journal | author=Zar S, Mincher L, Benson MJ, Kumar D | title=Food-specific IgG4 antibody-guided exclusion diet improves symptoms and rectal compliance in irritable bowel syndrome. | journal=Scandinavian Journal of Gastroenterlogy | year=2005 | pages=800–7 | volume=40 | issue=7 | id=PMID 16109655}}</ref>
===Bacterial overgrowth===
{{main|Small bowel bacterial overgrowth}}
More controversial is the connection between [[Small bowel bacterial overgrowth|bacterial overgrowth]] and irritable bowel syndrome.<ref name="pmid17043344">{{cite journal |author=Drossman DA |title=Treatment for bacterial overgrowth in the irritable bowel syndrome |journal=Ann. Intern. Med. |volume=145 |issue=8 |pages=626–8 |year=2006 |pmid=17043344 |doi=|url=http://www.annals.org/cgi/content/full/145/8/626}}</ref>
<ref name="pmid15316000">{{cite journal |author=Lin HC |title=Small intestinal bacterial overgrowth: a framework for understanding irritable bowel syndrome |journal=JAMA |volume=292 |issue=7 |pages=852–8 |year=2004 |pmid=15316000 |doi=10.1001/jama.292.7.852}}</ref> Between 10% and 80% of patients with irritable bowel syndrome have bacterial overgrowth as detected by the lactulose H<sub>2</sub> breath test.<ref name="pmid17043344"/> However, the accuracy of the lactulose H<sub>2</sub> breath test is disputed.<ref name="pmid17043344"/>
===Psychological stress===
[[Psychological stress]]—feeling mentally or emotionally tense, troubled, angry, or overwhelmed—may trigger symptoms in people with IBS. One study found that women with IBS have are more likely to report prior physical or sexual abuse; almost half of the patients reported prior abuse <ref name=pmid2240898>{{cite journal | author = Drossman D, Leserman J, Nachman G, Li Z, Gluck H, Toomey T, Mitchell C | title = Sexual and physical abuse in women with functional or organic gastrointestinal disorders. | journal = Ann Intern Med | volume = 113 | issue = 11 | pages = 828-33 | year = 1990 | id = PMID 2240898|pmid=2240898}}</ref>.
There are various ways that stress may interact with IBS. First, the colon has a vast supply of [[nerve]]s that connect it to the [[brain]]. These nerves control the normal rhythmic contractions of the colon and cause abdominal discomfort at stressful times. People often experience cramps or "butterflies" when they are nervous or upset. But with IBS, the colon can be overly responsive to even slight conflict or stress. Second, some evidence suggests that IBS is affected by the [[immune system]], which fights [[infection]] in the body. The immune system is also affected by stress. Third, the link between stress and IBS may be due to socially stressful situations making the mind more tuned to the sensations that arise in the colon and makes the stressed person perceive these sensations as unpleasant.<ref name="NIH2003-IBS"> [[National Institutes of Health]], 2003. ''Irritable Bowel Syndrome.'' Publication No. 03–693, April 2003.</ref>
There appears to be an overlap of IBS with [[psychological stress]], [[chronic pelvic pain]], [[fibromyalgia]], [[chronic fatigue syndrome]], the [[hypoglycemia#Hypoglycemia as American folk medicine|American folk medicine use of term hypoglycaemia]], and various [[mental disorder]]s (in a small minority). While no single explanation for this phenomenon exists, it does strengthen the view that there is a [[neurology|neurological]] and psychological component to IBS.  Recent studies indicate that presynaptic neural effects secondary to the release of histamine (part of immune response) is likely related to these problems.<ref name="pmid16531524">{{cite journal |author=Wood JD |title=Histamine, mast cells, and the enteric nervous system in the irritable bowel syndrome, enteritis, and food allergies |journal=Gut |volume=55 |issue=4 |pages=445–7 |year=2006 |pmid=16531524 |doi=10.1136/gut.2005.079046}}</ref>
It should be noted that the gut has its own nervous system - the [[enteric nervous system]] which has reciprocal connections to the main brain. The discovery of this system has lead to the development of the field of [[neurogastroenterology]].
For all these reasons, stress management is an important part of treatment for IBS. [[Stress management]] comprises:
*stress reduction (relaxation) training and relaxation therapies, such as [[meditation]]
*counseling and support
*regular exercise such as walking or [[yoga]]
*changes to the stressful situations in your life
*adequate [[sleep]]
===Hormones===
The role of [[hormone]]s in IBS is not yet fully understood. [[Menstruation]] frequently triggers or exacerbates IBS symptoms,<ref name="AmJGastro2003-Heitkemper">{{cite journal | author=Heitkemper MM, Cain KC, Jarrett ME, Burr RL, Hertig V, Bond EF | title=Symptoms across the menstrual cycle in women with irritable bowel syndrome | journal=Am J Gastroenterol | year=2003 | pages=420–30 | volume=98 | issue=2 | id=PMID 12591063}}</ref>
while [[pregnancy]] and [[menopause]] can either worsen or improve symptoms. [[Hormone replacement therapy]] is associated with an increased risk of developing IBS.<ref name="Maturitas2003-Ruigomez">{{cite journal | author=Ruigomez A, Garcia Rodriguez LA, Johansson S, Wallander MA | title=Is hormone replacement therapy associated with an increased risk of irritable bowel syndrome? | journal=Maturitas | year=2003 | pages=133–40 | volume=44 | issue=2 | id=PMID 12590009}}</ref>
==Treatment==
One of the most important therapeutic measures is reassuring the patient that they have no fatal or otherwise threatening disease, as this is the major concern of patients seeking medical help. Dietary advice may be given and medication is an option in most forms.
A questionnaire in 2006 designed to identify patients’ perceptions about IBS, their preferences on the type of information they need, as well as educational media and expectations from health care providers, revealed misperceptions about IBS developing into other conditions, including [[colitis]], [[malnutrition]], and [[cancer]].<ref name="JClinGastro2006-Halpert">{{cite journal | author=Halpert AD, Thomas AC, Hu Y, Morris CB, Bangdiwala SI, Drossman DA | title=A survey on patient educational needs in irritable bowel syndrome and attitudes toward participation in clinical research | journal=J Clin Gastroenterol | year=2006 | pages=37–43 | volume=40 | issue=1 | id=PMID 16340632}}</ref>
The survey found IBS patients were most interested in learning about foods to avoid (60%), causes of IBS (55%), medications (58%), coping strategies (56%), and psychological factors related to IBS (55%). The respondents indicated that they wanted their physician to be available via phone or e-mail following a visit (80%), have the ability to listen (80%), and provide hope (73%) and support (63%).
===Diet===
===Diet===
There are a number of dietary changes a person with IBS can make to prevent the overreaction of the gastrocolic reflex and lessen pain, discomfort, and bowel dysfunction. Having soluble fiber foods and supplements, substituting soy or rice products for dairy, being careful with fresh fruits and vegetables that are high in insoluble fiber, and eating regular small amounts, can all help to lessen the symptoms of IBS. Foods and beverages to be avoided or minimized include red meat, oily or fatty and fried products, dairy (even when there is no [[lactose intolerance]]), solid [[chocolate]], [[coffee]] (regular and decaffeinated), [[alcoholic beverage|alcohol]], carbonated beverages (especially those also containing [[sorbitol]]), and artificial sweeteners. However, care should be taken to avoid adding foods to the diet to which the patient is allergic or intolerant.<ref name="EatingForIBS2000-VanVorous">Van Vorous, Heather. ''Eating for IBS''. 2000. ISBN 1569246009. Excerpted with author's permission at [http://www.HelpForIBS.com/ Help for Irritable Bowel Syndrome] (see IBS Diet Section)</ref>
There are a number of dietary changes a person with IBS can make to prevent the overreaction of the gastrocolic reflex and lessen pain, discomfort, and bowel dysfunction. Having soluble fiber foods and supplements, substituting soy or rice products for dairy, being careful with fresh fruits and vegetables that are high in insoluble fiber, and eating regular small amounts, can all help to lessen the symptoms of IBS. Foods and beverages to be avoided or minimized include red meat, oily or fatty and fried products, dairy (even when there is no [[lactose intolerance]]), solid [[chocolate]], [[coffee]] (regular and decaffeinated), [[alcoholic beverage|alcohol]], carbonated beverages (especially those also containing [[sorbitol]]), and artificial sweeteners. However, care should be taken to avoid adding foods to the diet to which the patient is allergic or intolerant.<ref name="EatingForIBS2000-VanVorous">Van Vorous, Heather. ''Eating for IBS''. 2000. ISBN 1569246009. Excerpted with author's permission at [http://www.HelpForIBS.com/ Help for Irritable Bowel Syndrome] (see IBS Diet Section)</ref>
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;Fiber:
;Fiber:
In patients who do ''not'' have diarrhea predominant irritable bowel, soluble fiber at does of 20 grams per day can reduce overall symptoms but will not reduce pain. The research supporting [[dietary fiber]] contains conflicting, small studies that are complicated by the the heterogeneity of types of fiber and doses used <ref name=pmid14984370>{{cite journal | author = Bijkerk C, Muris J, Knottnerus J, Hoes A, de Wit N | title = Systematic review: the role of different types of fibre in the treatment of irritable bowel syndrome. | journal = Aliment Pharmacol Ther | volume = 19 | issue = 3 | pages = 245-51 | year = 2004 | id = PMID 14984370}}</ref>. The one [[meta-analysis]] that controlled for solubility found that only soluble fiber improved global symptoms of irritable bowel and neither type of fiber reduced pain <ref name=pmid14984370>.</ref>. Positive studies have used 20-30 grams per day of [[psyllium]] seed ([http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-psyllium.html also called ispaghula husk])<ref name=pmid3322956>{{cite journal | author = Prior A, Whorwell P | title = Double blind study of ispaghula in irritable bowel syndrome. | journal = Gut | volume = 28 | issue = 11 | pages = 1510-3 | year = 1987 | id = PMID 3322956}}</ref> <ref name=pmid2129822>{{cite journal | author = Jalihal A, Kurian G | title = Ispaghula therapy in irritable bowel syndrome: improvement in overall well-being is related to reduction in bowel dissatisfaction. | journal = J Gastroenterol Hepatol | volume = 5 | issue = 5 | pages = 507-13 | year = | id = PMID 2129822}}</ref>.  One study specifically examined the effect of dose and found that 20 grams of ispaghula husk was better than 10 grams and equivalent to 30 grams per day <ref name=pmid3030900>{{cite journal | author = Kumar A, Kumar N, Vij J, Sarin S, Anand B | title = Optimum dosage of ispaghula husk in patients with irritable bowel syndrome: correlation of symptom relief with whole gut transit time and stool weight. | journal = Gut | volume = 28 | issue = 2 | pages = 150-5 | year = 1987 | id = PMID 3030900}}</ref>An uncontrolled study noted increased symptoms with insoluble fibers. <ref name="BranIBS1994-Francis">{{cite journal | author=Francis CY, Whorwell PJ | title=Bran and irritable bowel syndrome: time for reappraisal | journal=Lancet | year=1994 | pages=39–40 | volume=344 | issue=8914 | id=PMID 7912305}}</ref><!-- originally listed as of Worrwell 1994, but see entry as per PubMed --> It is unclear if these symptoms are truly increased compared to a control group. If the symptoms are increased, it is unclear if these patients were diarrhea predominant (which can be exacerbated by fiber <ref name=pmid6365490>{{cite journal | author = Cann P, Read N, Holdsworth C, Barends D | title = Role of loperamide and placebo in management of irritable bowel syndrome (IBS). | journal = Dig Dis Sci | volume = 29 | issue = 3 | pages = 239-47 | year = 1984 | id = PMID 6365490}}</ref><ref name=pmid6319244>{{cite journal | author = Cann P, Read N, Holdsworth C | title = What is the benefit of coarse wheat bran in patients with irritable bowel syndrome? | journal = Gut | volume = 25 | issue = 2 | pages = 168-73 | year = 1984 | id = PMID 6319244}}</ref>), or if the increase is temporary before benefit occurs.
In patients who do ''not'' have diarrhea predominant irritable bowel, soluble fiber at does of 20 grams per day can reduce overall symptoms but will not reduce pain. The research supporting [[dietary fiber]] contains conflicting, small studies that are complicated by the the heterogeneity of types of fiber and doses used <ref name=pmid14984370>{{cite journal | author = Bijkerk C, Muris J, Knottnerus J, Hoes A, de Wit N | title = Systematic review: the role of different types of fibre in the treatment of irritable bowel syndrome. | journal = Aliment Pharmacol Ther | volume = 19 | issue = 3 | pages = 245-51 | year = 2004 | id = PMID 14984370}}</ref>. The one [[meta-analysis]] that controlled for solubility found that only soluble fiber improved global symptoms of irritable bowel and neither type of fiber reduced pain <ref name=pmid14984370>.</ref>. Positive studies have used 20-30 grams per day of [[psyllium]] seed ([http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-psyllium.html also called ispaghula husk])<ref name=pmid3322956>{{cite journal | author = Prior A, Whorwell P | title = Double blind study of ispaghula in irritable bowel syndrome. | journal = Gut | volume = 28 | issue = 11 | pages = 1510-3 | year = 1987 | id = PMID 3322956}}</ref> <ref name=pmid2129822>{{cite journal | author = Jalihal A, Kurian G | title = Ispaghula therapy in irritable bowel syndrome: improvement in overall well-being is related to reduction in bowel dissatisfaction. | journal = J Gastroenterol Hepatol | volume = 5 | issue = 5 | pages = 507-13 | year = | id = PMID 2129822}}</ref>.  One study specifically examined the effect of dose and found that 20 grams of ispaghula husk was better than 10 grams and equivalent to 30 grams per day <ref name=pmid3030900>{{cite journal | author = Kumar A, Kumar N, Vij J, Sarin S, Anand B | title = Optimum dosage of ispaghula husk in patients with irritable bowel syndrome: correlation of symptom relief with whole gut transit time and stool weight. | journal = Gut | volume = 28 | issue = 2 | pages = 150-5 | year = 1987 | id = PMID 3030900}}</ref>An uncontrolled study noted increased symptoms with insoluble fibers. <ref name="BranIBS1994-Francis">{{cite journal | author=Francis CY, Whorwell PJ | title=Bran and irritable bowel syndrome: time for reappraisal | journal=Lancet | year=1994 | pages=39–40 | volume=344 | issue=8914 | id=PMID 7912305}}</ref><!-- originally listed as of Worrwell 1994, but see entry as per PubMed --> It is unclear if these symptoms are truly increased compared to a control group. If the symptoms are increased, it is unclear if these patients were diarrhea predominant (which can be exacerbated by fiber <ref name=pmid6365490>{{cite journal | author = Cann P, Read N, Holdsworth C, Barends D | title = Role of loperamide and placebo in management of irritable bowel syndrome (IBS). | journal = Dig Dis Sci | volume = 29 | issue = 3 | pages = 239-47 | year = 1984 | id = PMID 6365490}}</ref><ref name=pmid6319244>{{cite journal | author = Cann P, Read N, Holdsworth C | title = What is the benefit of coarse wheat bran in patients with irritable bowel syndrome? | journal = Gut | volume = 25 | issue = 2 | pages = 168-73 | year = 1984 | id = PMID 6319244}}</ref>), or if the increase is temporary before benefit occurs.
===Medication===
====Initial treatments====
Medications may consist of stool softeners and [[laxative]]s in constipation-predominant IBS, and antidiarrheals (e.g., [[opioid]] or opioid [[analogs]] such as [[loperamide]] (Imodium®), or [[diphenoxylate]] (Lomotil®)) in diarrhea-predominant IBS for mild symptoms<ref name=pmid15846668>{{cite journal | author = Quartero A, Meineche-Schmidt V, Muris J, Rubin G, de Wit N | title = Bulking agents, antispasmodic and antidepressant medication for the treatment of irritable bowel syndrome. | journal = Cochrane Database Syst Rev | volume = | issue = | pages = CD003460 | year = | id = PMID 15846668}}</ref><ref name=pmid15606387>{{cite journal | author = Lesbros-Pantoflickova D, Michetti P, Fried M, Beglinger C, Blum A | title = Meta-analysis: The treatment of irritable bowel syndrome. | journal = Aliment Pharmacol Ther | volume = 20 | issue = 11-12 | pages = 1253-69 | year = 2004 | id = PMID 15606387}}</ref><ref name=pmid10896640>{{cite journal | author = Jailwala J, Imperiale T, Kroenke K | title = Pharmacologic treatment of the irritable bowel syndrome: a systematic review of randomized, controlled trials. | journal = Ann Intern Med | volume = 133 | issue = 2 | pages = 136-47 | year = 2000 | id = PMID 10896640}}</ref>.
;Anti-diarrheal agents:
[[Randomized controlled trial]]s have shown [[loperamide]] (Imodium®, others), which is available over-the-counter in the [[United States]], reduces diarrhea with an inconsistent effect on [[pain]].<ref name=pmid8734343>{{cite journal | author = Efskind P, Bernklev T, Vatn M | title = A double-blind placebo-controlled trial with loperamide in irritable bowel syndrome. | journal = Scand J Gastroenterol | volume = 31 | issue = 5 | pages = 463-8 | year = 1996 | id = PMID 8734343}}</ref>.
[[Diphenoxylate]] ((Lomotil®) is a synthetic [[opiate]] agonist available by prescription.
;Laxatives:
Regarding [[laxative]]s for patients who do not adequately respond to fiber, osmotic agents ([[polyethylene glycol]], [[sorbitol]], and [[lactulose]]) are good choices in order to avoid 'cathartic colon' which has been associated with stimulant laxatives <ref name=pmid9649012>{{cite journal | author = Joo J, Ehrenpreis E, Gonzalez L, Kaye M, Breno S, Wexner S, Zaitman D, Secrest K | title = Alterations in colonic anatomy induced by chronic stimulant laxatives: the cathartic colon revisited. | journal = J Clin Gastroenterol | volume = 26 | issue = 4 | pages = 283-6 | year = 1998 | id = PMID 9649012}}</ref>. Among the osmotic laxatives, one [[randomized controlled trial]] found greater improvement from 2 sachets (26 grams) of [[polyethylene glycol]] (PEG) versus or 2 sachets (20 grams) of [[lactulose]] <ref name=pmid9895382>{{cite journal | author = Attar A, Lémann M, Ferguson A, Halphen M, Boutron M, Flourié B, Alix E, Salmeron M, Guillemot F, Chaussade S, Ménard A, Moreau J, Naudin G, Barthet M | title = Comparison of a low dose polyethylene glycol electrolyte solution with lactulose for treatment of chronic constipation. | journal = Gut | volume = 44 | issue = 2 | pages = 226-30 | year = 1999 | id = PMID 9895382}}</ref>. Another [[randomized controlled trial]] found no difference between [[sorbitol]] and [[lactulose]] <ref name=pmid2122724>{{cite journal | author = Lederle F, Busch D, Mattox K, West M, Aske D | title = Cost-effective treatment of constipation in the elderly: a randomized double-blind comparison of sorbitol and lactulose. | journal = Am J Med | volume = 89 | issue = 5 | pages = 597-601 | year = 1990 | id = PMID 2122724}}</ref>. A second [[randomized controlled trial]] found benefit from a single daily dose of 17 grams. <ref name="pmid17403074">{{cite journal |author=Dipalma JA, Cleveland MV, McGowan J, Herrera JL |title=A randomized, multicenter, placebo-controlled trial of polyethylene glycol laxative for chronic treatment of chronic constipation |journal=Am. J. Gastroenterol. |volume=102 |issue=7 |pages=1436-41 |year=2007 |pmid=17403074 |doi=10.1111/j.1572-0241.2007.01199.x}}</ref>
;Antispasmodics:
Antispasmodics are either [[muscarinic antagonist]]s or calcium channel blockers (pinaverium, alverine) or serotonin receptor antagonosts (trimebutine) or combined muscarinic and calcium antagonist (propinox). The use of antispasmodic drugs (e.g. [[anticholinergic]]s such as [[hyoscine]]) may help patients, especially those with cramps or diarrhea.<ref name="pmid19008265 ">(2008) Brit Med J PMID: 19008265</ref> A [[meta-analysis]] by the [[Cochrane Collaboration]] concludes that if 6 patients are treated with antispasmodics, 1 patient will benefit ([[number needed to treat]] = 6)<ref name=pmid15846668 >used</ref>. Antispasmodic drugs are also available in combination with [[tranquilizers]] or [[barbiturates]], such as [[Librax]]® ([[chlordiazepoxide]] and [[clidinium]]) and [[Donnatal]]® (mixed [[salts]] of [[belladonna]] [[alkaloids]] and [[phenobarbital]]), respectively. However, the value of the combination therapies is not clear as the role of [[tranquilizers]] is not established.
====Drugs affecting serotonin (5-HT)====
Drugs affecting [[serotonin]] (5-HT) in the intestines can help reduce symptoms<ref name=pmid11755632>{{cite journal | author = Talley N | title = Serotoninergic neuroenteric modulators. | journal = Lancet | volume = 358 | issue = 9298 | pages = 2061-8 | year = 2001 | id = PMID 11755632}}</ref>. Serotonin stimulates the gut motility and so agonists can help constipation predominate irritable bowel while antagonists can help diarrhea predominant irritable bowel:
;Agonists:
*[[Tegaserod]], a selective 5-HT4 agonist for IBS-C, was available for relieving IBS constipation in women and chronic idiopathic constipation in men and women. The USA FDA has issued two warnings about the serious consequences of Tegaserod. In 2005, Tegaserod was rejected as an IBS medication by the European Union; however, it is available in some other countries, but is no longer available in the United States. Tegaserod, marketed as Zelnorm in the United States, was the only agent approved to treat the multiple symptoms of IBS (in women only), including constipation, abdominal pain and bloating. A [[meta-analysis]] by the [[Cochrane Collaboration]] concludes that if 17 patients are treated with typical doses of [[tegaserod]], 1 patient will benefit ([[number needed to treat]] = 17) <ref name=pmid14974049>{{cite journal | author = Evans B, Clark W, Moore D, Whorwell P | title = Tegaserod for the treatment of irritable bowel syndrome. | journal = Cochrane Database Syst Rev | volume = | issue = | pages = CD003960 | year = | id = PMID 14974049}}</ref>. In April of 2007, Tegaserod was removed from the U.S. market.<ref>http://www.fda.gov/cder/drug/infopage/zelnorm/default.htm</ref>
*[[Selective serotonin reuptake inhibitor]] [[anti-depressants]] (SSRIs), because of their serotonergic effect, would seem to help IBS, especially patients who are constipation predominant. Initial [[crossover studies]] <ref name=pmid16401691>{{cite journal | author = Tack J, Broekaert D, Fischler B, Oudenhove L, Gevers A, Janssens J | title = A controlled crossover study of the selective serotonin reuptake inhibitor citalopram in irritable bowel syndrome. | journal = Gut | volume = 55 | issue = 8 | pages = 1095-103 | year = 2006 | id = PMID 16401691}}</ref> and [[randomized controlled trials]] <ref name=pmid16128675>{{cite journal | author = Vahedi H, Merat S, Rashidioon A, Ghoddoosi A, Malekzadeh R | title = The effect of fluoxetine in patients with pain and constipation-predominant irritable bowel syndrome: a double-blind randomized-controlled study. | journal = Aliment Pharmacol Ther | volume = 22 | issue = 5 | pages = 381-5 | year = 2005 | id = PMID 16128675}}</ref> <ref name=pmid12557136>{{cite journal | author = Creed F, Fernandes L, Guthrie E, Palmer S, Ratcliffe J, Read N, Rigby C, Thompson D, Tomenson B | title = The cost-effectiveness of psychotherapy and paroxetine for severe irritable bowel syndrome. | journal = Gastroenterology | volume = 124 | issue = 2 | pages = 303-17 | year = 2003 | id = PMID 12557136}}</ref> <ref name=>{{cite journal | author = Tabas G, Beaves M, Wang J, Friday P, Mardini H, Arnold G | title = Paroxetine to treat irritable bowel syndrome not responding to high-fiber diet: a double-blind, placebo-controlled trial. | journal = Am J Gastroenterol | volume = 99 | issue = 5 | pages = 914-20 | year = 2004 | id = PMID 15128360}}</ref> support this role.
;Antagonists:
* [[Alosetron]], a selective 5-HT3 antagonist for IBS-D, which is only available for women in the United States under a restricted access program, due to severe risks of [[adverse drug reaction|side-effect]]s if taken mistakenly by IBS-A or IBS-C sufferers.
* [[Cilansetron]], also a selective 5-HT3 antagonist, is undergoing further clinical studies in Europe for IBS-D sufferers. In 2005, Solvay Pharmaceuticals withdrew Cilansetron from the United States regulatory approval process after receiving a "not approvable" action letter from the FDA requesting additional clinical trials.
====Other agents====
Anti-depressents include both [[tricyclic antidepressants]] (TCAs) and the newer [[selective serotonin reuptake inhibitors]] (SSRIs). In addition to improving symptoms via treating any co-existing depression, TCAs have anti-cholinergic actions while SSRIs are serotonergic. Thus in theory, TCAs would best treat diarrhea-predominant IBS while SSRIs would best treat constipation-predominant IBS. A [[meta-analysis]] of [[randomized controlled trial]]s of mainly TCAs found 3 patients have to be treated with TCAs for one patient to improve ([[number needed to treat]] = 3)<ref name=pmid11059442>{{cite journal | author = Jackson J, O'Malley P, Tomkins G, Balden E, Santoro J, Kroenke K | title = Treatment of functional gastrointestinal disorders with antidepressant medications: a meta-analysis. | journal = Am J Med | volume = 108 | issue = 1 | pages = 65-72 | year = 2000 | id = PMID 11059442}}</ref>. Subsequent [[randomized controlled trial]]s confirm that TCAs are best for patients with diarrhea-predominant IBS.<ref name="pmid18248658">{{cite journal |author=Vahedi H, Merat S, Momtahen S, ''et al'' |title=Clinical trial: the effect of amitriptyline in patients with diarrhoea-predominant irritable bowel syndrome |journal=Aliment. Pharmacol. Ther. |volume=27 |issue=8 |pages=678-84 |year=2008 |pmid=18248658 |doi=10.1111/j.1365-2036.2008.03633.x |url=http://www.blackwell-synergy.com/openurl?genre=article&sid=nlm:pubmed&issn=0269-2813&date=2008&volume=27&issue=8&spage=678}}</ref><ref name=pmid12851867>{{cite journal | author = Drossman D, Toner B, Whitehead W, Diamant N, Dalton C, Duncan S, Emmott S, Proffitt V, Akman D, Frusciante K, Le T, Meyer K, Bradshaw B, Mikula K, Morris C, Blackman C, Hu Y, Jia H, Li J, Koch G, Bangdiwala S | title = Cognitive-behavioral therapy versus education and desipramine versus placebo for moderate to severe functional bowel disorders. | journal = Gastroenterology | volume = 125 | issue = 1 | pages = 19-31 | year = 2003 | id = PMID 12851867}}</ref>. SSRIs are discussed above under 'Drugs affecting serotonin'.
Recent studies have suggested that [[rifaximin]], a non-absorbable antibiotic, can be used as an effective treatment for abdominal bloating and [[flatulence]] <ref name="AmJGastro2006-Sharara"> {{cite journal | author=Sharara AI, Aoun E, Abdul-Baki H, Mounzer R, Sidani S, Elhajj I | title=A randomized double-blind placebo-controlled trial of rifaximin in patients with abdominal bloating and flatulence | journal=Am J Gastroenterol | year=2006 | pages=326–33 | volume=101 | issue=2 | id=PMID 16454838}}</ref><ref name=pmid17043337>{{cite journal | author = Pimentel M, Park S, Mirocha J, Kane S, Kong Y | title = The effect of a nonabsorbed oral antibiotic (rifaximin) on the symptoms of the irritable bowel syndrome: a randomized trial. | journal = Ann Intern Med | volume = 145 | issue = 8 | pages = 557-63 | year = 2006 | id = PMID 17043337}}</ref>, giving more credibility to the potential role of bacterial overgrowth in some patients with IBS <ref name="AmJGastro2006-Quigley"> {{cite journal | author=Quigley EM | title=Germs, gas and the gut; the evolving role of the enteric flora in IBS | journal=Am J Gastroenterol | year=2006 | pages=334–5 | volume=101 | issue=2 | id=PMID 16454839}}</ref>.
Enteric coated [[peppermint]] oil capsules has been advocated for IBS symptoms in adults and children <ref name="AmFamPhysician2005-Hadley">{{cite journal | author=Hadley SK, Gaarder SM | title=Treatment of irritable bowel syndrome | journal=Am Fam Physician | year=2005 | pages=2501–6 | volume=72 | issue=12 | id=PMID 16370407}}</ref> and may be beneficial<ref name="pmid19008265 ">(2008) Brit Med J PMID: 19008265</ref><ref name=pmid3527248>{{cite journal | author = Nash P, Gould S, Bernardo D | title = Peppermint oil does not relieve the pain of irritable bowel syndrome. | journal = Br J Clin Pract | volume = 40 | issue = 7 | pages = 292-3 | year = 1986 | id = PMID 3527248}}</ref> <ref name=pmid9430014>{{cite journal | author = Liu J, Chen G, Yeh H, Huang C, Poon S | title = Enteric-coated peppermint-oil capsules in the treatment of irritable bowel syndrome: a prospective, randomized trial. | journal = J Gastroenterol | volume = 32 | issue = 6 | pages = 765-8 | year = 1997 | id = PMID 9430014}}</ref>. Peppermint may exacerbate [[gastroesophageal reflux disease]].
Lubiprostone may help constipation predominant irritable bowel in adult women.<ref name="urlFDA Approves Amitiza for IBS-C">{{cite web |url=http://www.fda.gov/bbs/topics/NEWS/2008/NEW01828.html |title=FDA Approves Amitiza for IBS-C |author=Anonymous |authorlink= |coauthors= |date= |format= |work= |publisher=Food and Drug Administration |pages= |language= |archiveurl= |archivedate= |quote= |accessdate=}}</ref>
Two [[randomized controlled trial]]s show reduction in gas by subjects taking oral alpha-galactosidase (Beano) <ref name="pmid17151807">{{cite journal |author=Di Stefano M, Miceli E, Gotti S, Missanelli A, Mazzocchi S, Corazza G |title=The effect of oral alpha-galactosidase on intestinal gas production and gas-related symptoms |journal=Dig Dis Sci |volume=52 |issue=1 |pages=78-83 |year=2007 |id=PMID 17151807}}</ref> <ref name="pmid7964541">{{cite journal |author=Ganiats T, Norcross W, Halverson A, Burford P, Palinkas L |title=Does Beano prevent gas? A double-blind crossover study of oral alpha-galactosidase to treat dietary oligosaccharide intolerance |journal=J Fam Pract |volume=39 |issue=5 |pages=441-5 |year=1994 |id=PMID 7964541}}</ref>; however, alpha-galactosidase may interfere with the diabetic medication [[acarbose]] <ref name="pmid9663365">{{cite journal |author=Lettieri J, Dain B |title=Effects of beano on the tolerability and pharmacodynamics of acarbose |journal=Clin Ther |volume=20 |issue=3 |pages=497-504 |year= |id=PMID 9663365}}</ref>.
For severe diarrhea-predominant IBS, more potent [[opioids]] may be used, such as [[codeine]] or [[propoxyphene]] (Darvon®); [[Refractory period|refractory]] cases may even be treated with [[paregoric]], or, more rarely, [[laudanum|deodorized tincture of opium]] or [[morphine sulfate]]. The use of opioids remains controversial due to the lack of evidence supporting their benefit and the potential risk of [[tolerance]], [[physical dependence]] and [[psychological dependence]] ([[addiction]]).
[[Cannabis]] has theoretical support for its role <ref name=pmid16133420>{{cite journal | author = Massa F, Storr M, Lutz B | title = The endocannabinoid system in the physiology and pathophysiology of the gastrointestinal tract. | journal = J Mol Med | volume = 83 | issue = 12 | pages = 944-54 | year = 2005 | id = PMID 16133420}}</ref><ref name=pmid15159679>{{cite journal | author = Russo E | title = Clinical endocannabinoid deficiency (CECD): can this concept explain therapeutic benefits of cannabis in migraine, fibromyalgia, irritable bowel syndrome and other treatment-resistant conditions? | journal = Neuro Endocrinol Lett | volume = 25 | issue = 1-2 | pages = 31-9 | year = | id = PMID 15159679}}</ref>, but has not been subject of clinical studies. Although illegal in the United States, it has been prescribed to patients in nations such as Canada. Some of the argued benefits of cannabis are the reduction of pain and nausea, appetite stimulation, and assisting in falling sleep.
===Psychotherapy and hypnotherapy===
There is a strong brain-gut component to IBS, and [[cognitive therapy]] may improve symptoms in a proportion of patients in conjunction with [[antidepressant]]s <ref name="BMJ2005-Kennedy">{{cite journal | author=Kennedy T, Jones R, Darnley S, Seed P, Wessely S, Chalder T | title=Cognitive behaviour therapy in addition to antispasmodic treatment for irritable bowel syndrome in primary care: randomised controlled trial | journal=BMJ | year=2005 | pages=435 | volume=331 | issue=7514 | id=PMID 16093252 [http://bmj.bmjjournals.com/cgi/content/full/331/7514/435 Full text]}}</ref>. In a [[randomized controlled trial]] of referred patients, [[cognitive behavioral therapy]] helped even though patients in this study ''did not'' have any psychiatric diagnoses <ref name=pmid10763948>{{cite journal | author = Heymann-Mönnikes I, Arnold R, Florin I, Herda C, Melfsen S, Mönnikes H | title = The combination of medical treatment plus multicomponent behavioral therapy is superior to medical treatment alone in the therapy of irritable bowel syndrome. | journal = Am J Gastroenterol | volume = 95 | issue = 4 | pages = 981-94 | year = 2000 | id = PMID 10763948}}</ref>.
Gut-directed or gut-specific [[hypnotherapy]] or self-hypnosis is one of the most promising areas of IBS treatment. Current research shows that symptom reduction/elimination from IBS hypnotherapy can last at least five years <ref name="Gut2003-Gonsalkorale"> {{cite journal | author=Gonsalkorale WM, Miller V, Afzal A, Whorwell PJ | title=Long term benefits of hypnotherapy for irritable bowel syndrome | journal=Gut | year=2003 | pages=1623–9 | volume=52 | issue=11 | id=PMID 14570733}}</ref>.
===Alternative treatments===
;Probiotics:
[[Probiotics]] are generally accepted to be potentially beneficial strains of [[bacteria]] and [[yeast]], often found in the human gut. [[Lactobacillus plantarum]] (LP299V) has shown inconsistent results in randomized controlled trials with a positive<ref name="pmid11711768"> {{cite journal | author=Niedzielin K, Kordecki H, Birkenfeld B | title=A controlled, double-blind, randomized study on the efficacy of [[Lactobacillus]] plantarum 299V in patients with irritable bowel syndrome | journal=Eur J Gastroenterol Hepatol | year=2001 | pages=1143–7 | volume=13 | issue=10 | id=PMID 11711768}}</ref> and a negative<ref name="pmid12452404">{{cite journal |author=Sen S, Mullan MM, Parker TJ, Woolner JT, Tarry SA, Hunter JO |title=Effect of Lactobacillus plantarum 299v on colonic fermentation and symptoms of irritable bowel syndrome |journal=Dig. Dis. Sci. |volume=47 |issue=11 |pages=2615–20 |year=2002 |pmid=12452404 |doi=}}</ref> study. Bifidobacterium animalis DN-173 010 benefited patients in a [[randomized controlled trial]]. <ref name="pmid17635382">{{cite journal |author=Guyonnet D, Chassany O, Ducrotte P, ''et al'' |title=Effect of a fermented milk containing Bifidobacterium animalis DN-173 010 on the health-related quality of life and symptoms in irritable bowel syndrome in adults in primary care: a multicentre, randomized, double-blind, controlled trial |journal=Aliment. Pharmacol. Ther. |volume=26 |issue=3 |pages=475-86 |year=2007 |pmid=17635382 |doi=10.1111/j.1365-2036.2007.03362.x}} PMID 17635382</ref> Another study showed the utility of B. infantis 35625, a strain of [[Bifidobacteria]] in normalizing bowel movement frequency in IBS <ref name="AmColGastro2005-StudiesProbiotics">[http://www.acg.gi.org/media/releases/ACG05Release_ProbioticsinIBS.pdf New Studies Examine the Evidence of Probiotics on IBS] (Oct 2005). American College of Gastrointerologists. Retrieved on [[March 2]], [[2006]]</ref>. A multispecies probiotic supplementation helped symptoms in a [[randomized controlled trial]].<ref name="pmid17919270">{{cite journal |author=Kajander K, Myllyluoma E, Rajilić-Stojanović M, ''et al'' |title=Clinical trial: multispecies probiotic supplementation alleviates the symptoms of irritable bowel syndrome and stabilizes intestinal microbiota |journal=Aliment. Pharmacol. Ther. |volume=27 |issue=1 |pages=48–57 |year=2008 |pmid=17919270 |doi=10.1111/j.1365-2036.2007.03542.x}}</ref> A meta-analysis suggests benefit.<ref name="pmid18363533">{{cite journal |author=Wilhelm SM, Brubaker CM, Varcak EA, Kale-Pradhan PB |title=Effectiveness of probiotics in the treatment of irritable bowel syndrome |journal=Pharmacotherapy |volume=28 |issue=4 |pages=496–505 |year=2008 |month=April |pmid=18363533 |doi=10.1592/phco.28.4.496 |url=http://www.extenza-eps.com/doi/abs/10.1592/phco.28.4.496 |issn=}}</ref>
Although not studied in a controlled trial, a strain of [[Lactobacillus]] known as "LGG" may be able to endure the acidic environment of the stomach and survive until presentation to the intestinal tract <ref name="EaseThePain2006-Weil">[http://www.prevention.com/article/0,5778,s1-1-77-333-2868-1,00.html Ease the pain of IBS], (2006). Andrew Weil. Retrieved on [[March 2]], [[2006]]</ref><!-- not entirely clear where this citation was linked to -->.
;Prebiotics
Prebiotics are short-chain carbohydrates that may benefit gut microbiota.<ref name="pmid16918875">{{cite journal |author=Macfarlane S, Macfarlane GT, Cummings JH |title=Review article: prebiotics in the gastrointestinal tract |journal=Aliment. Pharmacol. Ther. |volume=24 |issue=5 |pages=701–14 |year=2006 |pmid=16918875 |doi=10.1111/j.1365-2036.2006.03042.x}}</ref>
;Acupuncture:
Many sufferers of IBS seek relief using [[Acupuncture]], a component of [[Traditional Chinese Medicine]] and a discipline representing some of the oldest and most used medical procedures in the world. The [[meta-analysis]] by the [[Cochrane Collaboration]] concluded 'Most of the trials included in this review were of poor quality and were heterogeneous in terms of interventions, controls, and outcomes measured. With the exception of one outcome in common between two trials, data were not combined. Therefore, it is still inconclusive whether acupuncture is more effective than sham acupuncture or other interventions for treating IBS'<ref name=pmid17054239>{{cite journal | author = Lim B, Manheimer E, Lao L, Ziea E, Wisniewski J, Liu J, Berman B | title = Acupuncture for treatment of irritable bowel syndrome. | journal = Cochrane Database Syst Rev | volume = | issue = | pages = CD005111 | year = | id = PMID 17054239}}</ref>. Acupuncture continues to find increasingly widespread acceptance in the United States, and it is estimated that nearly 8.7 million Americans have sought its benefits <ref name="HSTAT1997-Culliton">{{cite journal | author=Culliton BJ | title=NIH says "yes" to acupuncture | journal=Nat Med | year=1997 | pages=1307 | volume=3 | issue=12 | id=PMID 9396586}} from {{cite book  |  author=Culliton BJ | year=1997  | title=Health Services/Technology Assessment Text (HSTAT) | url=http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat  | chapter=107. Acupuncture | hapterurl=http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat4.chapter.18129 | publisher=National Information Center on Health Services Research and Health Care Technology}}</ref>. One practitioner of Tradtional Chinese Medicine asserts that IBS has become a bit of a "garbage diagnosis" for some medical practitioners. Traditional Chinese Medicine does not recognize the Western diagnosis of IBS per se, as the named condition has no definitive single test for diagnosis, clear cause, or cure. Traditional Chinese Medicine approaches IBS on an individual symptom-by-symptom basis, rather than recognizing a standard "IBS" diagnosis, which then warrants a blanket "IBS" treatment <ref name="IBSTCM2006-Stone"> [http://beyondwellbeing.com/ibs/ Irritable Bowel Syndrome - A Traditional Chinese Medicine Perspective], (2006). Al Stone L.Ac. Retrieved on [[February 14]], [[2006]].</ref>. The concept of [[Qi]] is important in [[Acupuncture]], as obstructions to its proper flow throughout the body are considered a contributing factor to illness. Details of the specific mechanisms through which Qi function remain as yet unexplained by Western scientific methods. According to the National Institutes of Health, "Preclinical studies have documented acupuncture's effects, but they have not been able to fully explain how acupuncture works within the framework of the Western system of medicine that is commonly practiced in the United States." <ref name="NCCAM2006-Acupuncture">[http://nccam.nih.gov/health/acupuncture/ Get the Facts, Acupuncture], (2006). National Institute of Health. Retrieved on [[March 2]], [[2006]].</ref>.
==Epidemiology==
Point [[prevalence]] is 10–20% of the general population of Western countries with a much higher lifetime prevalence. Prevalence is similar in India, Japan and China. IBS is less common in Thailand and rural South African areas. In Western countries, but not in India or Sri Lanka, females have a greater risk of developing IBS.
Of the persons who have symptoms of IBS, only a proportion seeks medical help. However, there is not yet a predictor known for who will seek medical help and who will not.
==Prognosis==
IBS is not fatal nor is it linked to the development of other serious bowel diseases. However, due to the chronic pain, discomfort, and other symptoms, work absenteeism, social phobias, and other negative quality-of-life effects can be common in more serious cases.  Individuals who find a caring primary caregiver and/or sufficient self-help options should be able to develop a successful treatment program for their symptoms and lead normal lives.
== References ==
<references/>
==External links==
* [http://www.romecriteria.org/ Rome II Diagnostic Criteria for the Functional Gastrointestinal Disorders]
* [http://www.ibsnetwork.org.uk/ The IBS Network] - provides support to people with IBS in the UK
* [http://www.scottish-ibs.org.uk/ Scottish IBS Support Group]
*[http://www.gesundheitsinformation.de/fact-sheet.278.195.en.html Irritable bowel syndrome at informedhealthonline.org]

Revision as of 11:57, 14 November 2008

Diet

There are a number of dietary changes a person with IBS can make to prevent the overreaction of the gastrocolic reflex and lessen pain, discomfort, and bowel dysfunction. Having soluble fiber foods and supplements, substituting soy or rice products for dairy, being careful with fresh fruits and vegetables that are high in insoluble fiber, and eating regular small amounts, can all help to lessen the symptoms of IBS. Foods and beverages to be avoided or minimized include red meat, oily or fatty and fried products, dairy (even when there is no lactose intolerance), solid chocolate, coffee (regular and decaffeinated), alcohol, carbonated beverages (especially those also containing sorbitol), and artificial sweeteners. However, care should be taken to avoid adding foods to the diet to which the patient is allergic or intolerant.[1]

Definitive determination of dietary issues can be accomplished by testing for the physiological effects of specific foods. The ELISA food allergy panel can identify specific foods to which a patient has a reaction. Other testing can determine if there are nutritional deficiencies secondary to diet that may also play a role. Removal of foods causing IgG immune response as measured using the ELISA food panel has been shown to substantially decrease symptoms of IBS in several studies.[2]

There is no evidence that digestion of food or absorption of nutrients is problematic for those with IBS at rates different from those without IBS. However, the very act of eating or drinking can provoke an overreaction of the gastrocolic response in some patients with IBS due to their heightened visceral sensitivity, and this can lead to abdominal pain, diarrhea, and/or constipation.[3]

Several of the most common dietary triggers are well-established by clinical studies at this point; research has shown that IBS patients are hypersensitive to fats and fructose. [4] [5]

It also appears that some foods are more difficult for the gut as evidenced by elevated food-specific IgG4 antibodies being present,[6] [7] while others increase colonic contractions, which may be painful, due to increased visceral sensitivity in IBS sufferers. [8]

Fiber

In patients who do not have diarrhea predominant irritable bowel, soluble fiber at does of 20 grams per day can reduce overall symptoms but will not reduce pain. The research supporting dietary fiber contains conflicting, small studies that are complicated by the the heterogeneity of types of fiber and doses used [9]. The one meta-analysis that controlled for solubility found that only soluble fiber improved global symptoms of irritable bowel and neither type of fiber reduced pain [9]. Positive studies have used 20-30 grams per day of psyllium seed (also called ispaghula husk)[10] [11]. One study specifically examined the effect of dose and found that 20 grams of ispaghula husk was better than 10 grams and equivalent to 30 grams per day [12]An uncontrolled study noted increased symptoms with insoluble fibers. [13] It is unclear if these symptoms are truly increased compared to a control group. If the symptoms are increased, it is unclear if these patients were diarrhea predominant (which can be exacerbated by fiber [14][15]), or if the increase is temporary before benefit occurs.

  1. ↑ Van Vorous, Heather. Eating for IBS. 2000. ISBN 1569246009. Excerpted with author's permission at Help for Irritable Bowel Syndrome (see IBS Diet Section)
  2. ↑ Atkinson W, Sheldon TA, Shaath N, Whorwell PJ (2004). "Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial". Gut 53 (10): 1459–64. PMID 15361495 Full text.
  3. ↑ Sjölund K, Ekman R, Lindgren S, Rehfeld J (1996). "Disturbed motilin and cholecystokinin release in the irritable bowel syndrome.". Scand J Gastroenterol 31 (11): 1110-4. PMID 8938905.
  4. ↑ Caldarella MP, Milano A, Laterza F, Sacco F, Balatsinou C, Lapenna D, Pierdomenico SD, Cuccurullo F, Neri M (2005). "Visceral sensitivity and symptoms in patients with constipation- or diarrhea-predominant irritable bowel syndrome (IBS): effect of a low-fat intraduodenal infusion". Am J Gastroenterol 100 (2): 383–9. PMID 15667496.
  5. ↑ Choi, Y. Fats, Fructose May Contribute to IBS Symptoms. ACG 68th Annual Scientific Meeting: Abstract 21, presented October 13, 2003; Abstract 547, presented October 14, 2003.
  6. ↑ Zar S, Benson MJ, Kumar D (2005). "Food-specific serum IgG4 and IgE titers to common food antigens in irritable bowel syndrome". Am J Gastroenterol 100 (7): 1550–7. PMID 15984980.
  7. ↑ Zar S, Mincher L, Benson MJ, Kumar D (2005). "Food-specific IgG4 antibody-guided exclusion diet improves symptoms and rectal compliance in irritable bowel syndrome". Scand J Gastroenterol 40 (7): 800–7. PMID 16109655.
  8. ↑ Mayer EA, Berman S, Suyenobu B, Labus J, Mandelkern MA, Naliboff BD, Chang L (2005). "Differences in brain responses to visceral pain between patients with irritable bowel syndrome and ulcerative colitis". Pain 115 (3): 398–409. PMID 15911167.
  9. ↑ 9.0 9.1 Bijkerk C, Muris J, Knottnerus J, Hoes A, de Wit N (2004). "Systematic review: the role of different types of fibre in the treatment of irritable bowel syndrome.". Aliment Pharmacol Ther 19 (3): 245-51. PMID 14984370. Cite error: Invalid <ref> tag; name "pmid14984370" defined multiple times with different content
  10. ↑ Prior A, Whorwell P (1987). "Double blind study of ispaghula in irritable bowel syndrome.". Gut 28 (11): 1510-3. PMID 3322956.
  11. ↑ Jalihal A, Kurian G. "Ispaghula therapy in irritable bowel syndrome: improvement in overall well-being is related to reduction in bowel dissatisfaction.". J Gastroenterol Hepatol 5 (5): 507-13. PMID 2129822.
  12. ↑ Kumar A, Kumar N, Vij J, Sarin S, Anand B (1987). "Optimum dosage of ispaghula husk in patients with irritable bowel syndrome: correlation of symptom relief with whole gut transit time and stool weight.". Gut 28 (2): 150-5. PMID 3030900.
  13. ↑ Francis CY, Whorwell PJ (1994). "Bran and irritable bowel syndrome: time for reappraisal". Lancet 344 (8914): 39–40. PMID 7912305.
  14. ↑ Cann P, Read N, Holdsworth C, Barends D (1984). "Role of loperamide and placebo in management of irritable bowel syndrome (IBS).". Dig Dis Sci 29 (3): 239-47. PMID 6365490.
  15. ↑ Cann P, Read N, Holdsworth C (1984). "What is the benefit of coarse wheat bran in patients with irritable bowel syndrome?". Gut 25 (2): 168-73. PMID 6319244.
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