World Gastroenterology Organisation Global Guidelines Irritable Bowel Syndrome

Abstract

WGO IRRITABLE BOWEL SYNDROME (IBS) CASCADES Cascade Options for Resource-sensitive IBS Diagnosis High Resource Levels History, physical examination, exclusion of alarm symptoms, consideration of psychological factors. Full blood count (FBC), erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP), stool studies (white blood cells, ova, parasites, occult blood). Selenium homocholic acid taurine (tauroselcholic acid) test (SeHCAT; incorporating selenium-75) for the investigation of bile acid malabsorption (BAM) and measurement of bile acid pool loss. This test may have limited availability, even in areas with high resources. Thyroid function. Tissue transglutaminase antibody to screen for celiac disease. Esophagogastroduodenoscopy and distal duodenal biopsy in patients with diarrhea, to rule out celiac disease, tropical sprue, giardiasis, and in patients in whom abdominal pain and discomfort is located more in the upper abdomen. Colonoscopy and biopsy. Fecal inflammation marker (eg, calprotectin or lactoferrin) to distinguish IBS from inflammatory bowel disease (IBD) where the latter is prevalent. Hydrogen breath test for lactose intolerance and small-intestinal bacterial overgrowth (SIBO). Medium Resource Levels History, physical examination, exclusion of alarm symptoms, consideration of psychological factors. FBC, ESR or CRP, stool studies, thyroid function. Sigmoidoscopy. Low Resource Levels History, physical examination, exclusion of alarm symptoms, consideration of psychological factors. FBC, ESR, and stool examination. Note: Even in “wealthy” countries, not all patients need colonoscopy, which should be reserved in particular for those with alarm symptoms or signs and those over the age of 50. The need for investigations and for sigmoidoscopy and colonoscopy, in particular, should also be dictated by the characteristics of the patient (presenting features, age, etc.) and the geographical location (ie, whether or not in an area of high prevalence for IBD, celiac disease, colon cancer, or parasitosis). In general, the diagnosis is “safer” in patients with constipation, whereas in patients with severe diarrhea, there is a greater need to consider tests to exclude organic pathology. Cascade Options for Resource-sensitive IBS Management High Resource Levels Reassurance, dietary and lifestyle review, and counseling. Try a quality probiotic with proven efficacy. Symptomatic treatment of: Pain, with a locally available antispasmodic; for more severely affected patients, a low-dose tricyclic antidepressant (TCA) or selective serotonin reuptake inhibitor (SSRI) should be added. Constipation with dietary measures and fiber supplementation, progressing to osmotic laxatives such as lactulose. Although the evidence to support their use is weak, it may be worth addressing diarrhea with simple antidiarrheals. Psychological approaches (hypnotherapy, psychotherapy, group therapy) should be considered and consultation with a dietitian, where indicated. Add specific pharmacological agents, where approved: Lubiprostone or linaclotide for IBS with constipation (IBS-C). Rifaximin for diarrhea and bloating. Alosetron and eluxadoline for IBS with diarrhea (IBS-D). Medium Resource Levels Reassurance, dietary and lifestyle review, and counseling. Add a quality probiotic with proven efficacy. Symptomatic treatment of: Pain, with a locally available antispasmodic; for more severely affected patients, a low-dose TCA should be added. Constipation with dietary measures and fiber supplementation. Although the evidence to support their use is weak, it may be worth addressing diarrhea with bulking agents and simple antidiarrheals. Low Resource Levels Reassurance, dietary and lifestyle review, and counseling. Symptomatic treatment of: Pain, with a locally available antispasmodic. Constipation, with dietary measures and fiber supplementation. Although the evidence to support their use is weak, it may be worth addressing diarrhea with bulking agents and simple antidiarrheals. INTRODUCTION Definition: IBS is a functional bowel disorder in which abdominal pain or discomfort is associated with defecation and/or a change in bowel habit. Sensations of discomfort (bloating), distension, and disordered defecation are commonly associated features. In some languages, the words “bloating” and “distension” may be represented by the same term. IBS is not known to be associated with an increased risk for the development of cancer or IBD, or with increased mortality. It generates significant direct and indirect health care costs. Although visceral hypersensitivity is accepted as prevalent, no universal pathophysiological substrate has been demonstrated in IBS.1 A transition of IBS to, and overlap with, other symptomatic gastrointestinal disorders (eg, gastroesophageal reflux disease, dyspepsia, and functional constipation) may occur. IBS usually causes long-term symptoms, which may occur in episodes. Symptoms vary and are often associated with food intake and, characteristically, with defecation. They interfere with daily life and social functioning in many patients. Symptoms sometimes develop as a consequence of an intestinal infection [postinfectious IBS (PI-IBS)] or are precipitated by major life events, occur during a period of considerable stress, or develop following abdominal and/or pelvic surgery. They may also be precipitated by antibiotic treatment. In general, there is a lack of recognition of the condition; many patients with IBS symptoms do not consult a physician and are not formally diagnosed. IBS Subclassification According to the Rome III criteria, IBS may be subtyped or subclassified on the basis of the patient’s stool characteristics, as defined by the Bristol Stool Scale: IBS-D: Loose stools >25% of the time and hard stools <25% of the time. Up to one third of cases. More common in men. IBS-C: Hard stools >25% of the time and loose stools <25% of the time. Up to one third of cases. More common in women. IBS with mixed bowel habits or cyclic pattern (IBS-M): Both hard and soft stools >25% of the time. One third to one half of cases. Unsubtyped IBS: Insufficient abnormality of stool consistency to meet criteria IBS-C or IBS-M It must be remembered, however, that patients commonly transition between these subtypes and that the symptoms of diarrhea and constipation are commonly misinterpreted in IBS patients. Thus, many IBS patients who complain of “diarrhea” are referring to the frequent passage of formed stools and, in the same patient population, “constipation” may refer to any one of a variety of complaints associated with the attempted act of defecation and not simply to infrequent bowel movements. In addition, bowel habit must be evaluated without using antidiarrheals or laxatives. On clinical grounds, other subclassifications may be developed, whether based on symptoms (eg, with predominant bowel dysfunction pain or bloating) or on precipitating factors [PI-IBS, food induced (meal induced), or stress related]. However, with the exception of PI-IBS, which is quite well characterized, the relevance of any of these other classifications to the prognosis or response to therapy in patients with IBS remains to be defined. It must also be remembered that the Rome III criteria are not commonly used in clinical practice. Furthermore, cultural issues may inform symptom reporting. In India, for example, a patient who reports straining or passing hard stools (often with a feeling of incomplete evacuation) is likely to complain of constipation even if he or she passes stools more than once daily. Finally, there is considerable overlap and a tendency to transition between IBS-C and functional constipation. Global Prevalence and Incidence The global picture of the prevalence of IBS is far from complete, as no data are available from several regions. In addition, comparisons of data from different regions are often problematic due to the use of different diagnostic criteria (in general, the “looser” the criteria, the higher the prevalence), as well as the influence of other factors such as population selection, the inclusion or exclusion of comorbid disorders (eg, anxiety), access to health care, and cultural influences. In Mexico, for example, the prevalence of IBS in the general population, measured using the Rome II criteria, was 16%, but the figure increased to 35% among individuals in a university-based community. What is remarkable is that the available data suggest that the prevalence is quite similar across many countries, despite substantial lifestyle differences. The prevalence of IBS in Europe and North America is estimated to be 10% to 15%. In Sweden, the most commonly cited figure is 13.5%. The prevalence of IBS is increasing in countries in the Asia-Pacific region, particularly in those with developing economies. Estimates of the prevalence of IBS (using the Rome II diagnostic vary in the Asia-Pacific from that the Rome criteria for IBS more patients than the Rome II prevalence in in in in in and in A in that the prevalence of as defined by the Rome III criteria, in individuals was data from America are but may be to a as many studies are not in or are not cited in commonly used (eg, In for example, an prevalence of in and in with IBS-C and with In of the the age of was a from an IBS prevalence of with of those affected and on in America a high prevalence of which was similar to that in the of the from are A in a population a based on the Rome II A among in the same based on the same criteria, a prevalence of on IBS IBS between the of and The of patients to a physician is usually in the to age group but in some symptoms may to Prevalence is higher in is not in some studies from India, for Although the estimated prevalence of IBS in is similar to that in to be among IBS in Global also and comparisons of studies based on and are with IBS symptoms are common in population but the of with IBS are not diagnosed. 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A diagnosis of celiac disease is in the of or transglutaminase but their the of tropical The between IBS and is is disease no more than IBS in a patient who has In the symptoms and/or are and to during an abdominal and the of a inflammatory in the However, it is that patients may have more symptoms in between and that and but not disease, may the risk for be by the of abdominal pain and the of or to the on examination. the symptoms and/or abdominal and pain or and on examination. In over the age of cancer should be considered in the In the following symptoms more common among with increased abdominal and pelvic The of increased abdominal and symptoms was in of with cancer, but in of a This may for diarrhea in patients who are treatment from and with overlap to have more severe Thus, has been in to to of IBS patients and IBS is common in several other pain such as pelvic pain as well as and and In a the prevalence of celiac disease was to be higher in patients who the diagnostic criteria for IBS than in individuals without is a higher prevalence of constipation in patients with between IBS-C and constipation may be in clinical several studies have the and of to be an between these functional gastrointestinal The prevalence of gastroesophageal symptoms in patients with IBS is higher than in those without is an overlap between the in to of It is that patients with symptoms of should screen for gastroesophageal reflux Symptoms with IBS have been to be higher in patients with in with even among those to be in symptoms also to be more common in patients with disease than in those with and in those with a diagnosis of IBS not be in a patient with IBS that there is no general on the of it as no that no treatment is the as to the of all IBS patients. also the common between IBS symptoms and such factors as stress, and psychological should be to measures that may if not such between different countries and be to have a significant influence on the prevalence of symptoms of but is data on in the intestinal in IBS have in and a for in but also it that the of in as are and the of specific vary the of quality also to in IBS patients commonly have to a variety of the In (in and for example, are available and commonly used for However, their is to as the of vary on the have been to the of a in factors are often but are of in the of The is and should to several during the and in the and the patient’s A should be with the patient’s symptoms and accepted as and the of should be to the patient’s to symptoms and with the to and in to and to factors. should be to may that are the symptoms, but has a influence on the on and should be A or a (eg, with intake of to be a in but the general of fiber in IBS is not may symptoms and and distension, and in particular, may the use of if in fiber intake are not such as in in in and abdominal pain and and the stool but long-term and the of to be It is also whether the is to all IBS Although are in North America and the of or in IBS is global of symptoms in and symptoms such as and However, the of these and the of the most are not The of is to as different and of have been used in Furthermore, most studies of in IBS have been of have not used an and have not is evidence for a general of or in patients with A on the use of specific in the of A variety of agents are used the for the treatment of symptoms in for bulking agents, the and the linaclotide for constipation, bulking agents, the antibiotic and a and for and symptomatic in are more common with than with a is to in IBS The risk of is no greater with than with a and are for symptom in are with and the most and may patient are associated with significant in and should be in should for patients who from may be considered in it is not that should be for IBS in patients without comorbid of and limited data and long-term Rifaximin is in symptoms in Rifaximin may be considered as a patients and to have higher response Rifaximin is well but and have not been However, and has been It has also been that patients for Alosetron is for therapy of However, it has been associated with an increased risk of and may severe should for patients who from Lubiprostone is and for treatment of has been the major is and for treatment of is the major of studies are to long-term and However, there is evidence to for use in mixed are no more than symptoms of and and have no in Although there is no evidence that symptoms in patients with it may was to diarrhea, and in but not any in to where should also be considered as therapy in it has also been to be in and to be of such as severe constipation and an is is to are to be all as and are a significant risk in such a and also have on the gastrointestinal The probiotic has been to and and stool habit in of predominant bowel but is available in the the and The probiotic has been to gastrointestinal and to stool among IBS patients with constipation. Although osmotic laxatives are often have been formally Lubiprostone and linaclotide have been for the treatment of Although it is an for the treatment of diarrhea, of the lack of on the symptom of there is evidence to for use in Alosetron is for with severe with symptoms and no response to and have been in the for it is to their in IBS and that such as the may be in some patients. is no evidence to support the use of and other agents in specific probiotic such as and the probiotic have clinical evidence of for distension, and such as as well as the other symptoms of treatment with has been to in some IBS patients. patients and have been to have higher response Rifaximin has been to be on patients who have a Psychological from the general approaches for the of the in more psychological may be in and on the of and approaches may in group or has but limited and are and and should be for patients with IBS to It has a high of and and there is evidence of in to It should be by with in the treatment is more time than and as by patients, by and should be with However, there is limited evidence from are that use diagnostic criteria, have of and and The limited and of The of that psychological psychotherapy, and but not are more than care in global symptoms of However, that the quality of evidence was and that the to care or the exception of a these have not been to be to The of their is to and the that the available to a It was not to these studies a however, and any of therapy in IBS to be by the used and their there are significant with the use of any A of of was due to is any on or therapy be most patients with symptoms are likely to but not Symptoms in a and some patients that may the prognosis to IBS symptoms, as a of symptoms, a of symptoms, life stress, and In the physician treatment by the the patient IBS and In there is no need for in the symptoms and/or are by considerable or diarrhea, or constipation do not to therapy or signs One should of that an disorder patients with IBS some of dietary and to or of of and dietary The tendency for disorders to develop is more common in IBS patients.