ACG Releases Evidence-Based Systematic Review on Management of Irritable Bowel Syndrome
New Graded Recommendations Clarify the Clinical Options for Physicians and Patients
The College’s evidence-based position statement on IBS offers new graded recommendations on testing and treatment of this chronic, recurrent functional disorder of the gastrointestinal tract that affects all aspects of daily life for its sufferers. In order to critically evaluate the rapidly expanding research about IBS and to assess the evidence of efficacy of new IBS drugs, the ACG IBS Task Force performed a comprehensive meta-analysis of the evidence on therapies for IBS.
The College’s new recommendations include expert assessments of traditional therapies for IBS, as well as a range of new treatments, including evidence on probiotics; the non-absorbable antibiotic rifaximin; antidepressants; antispasmodics and peppermint oil; fiber, bulking agents and laxatives; antidiarrheals, including loperamide; the 5-HT3 receptor antagonist alosetron; the 5-HT4 (serotonin) receptor agonist tegaserod; the chloride channel activator lubiprostone; psychologic therapies; herbal preparations and acupuncture. The evidence-based review also includes new recommendations about the routine use of diagnostic tests for patients who present with IBS symptoms, as well as food allergy testing and diet in IBS.
“For the gastroenterologist seeing patients with IBS, the new ACG recommendations specify whether or not the range of potential therapies are better than placebo for resolving IBS symptoms,” said
“The College’s graded recommendations on IBS take into account the quality of the evidence, such as the strength of study design, and the magnitude of benefit of different treatments. The benefits of treatment must be balanced against any potential risks,” explained Dr. Brandt.
“This new meta-analysis of the literature on the diagnosis and therapy of IBS offers physicians the opportunity to make clinical decisions about IBS based on a thorough assessment of the evidence,” explained ACG President Dr.
The ACG Evidence-Based Systematic Review on IBS can be accessed at http://www.acg.gi.org/media/releases/ajg_ibs_supp_0109.pdf
Highlights of ACG’s New Recommendations on IBS Therapies
In general, treatments for IBS are directed towards the patient’s predominant symptoms. There are a wide variety of available therapies, many of which improve individual IBS symptoms. Only a small number of therapies has been shown to be of benefit for global symptoms of IBS.
– Trials suggest psyllium, fiber, certain antispasmodics, and peppermint oil are effective in IBS patients although the quality of the evidence is poor.
– Evidence suggests that some probiotics may be effective in reducing overall IBS symptoms but more data are needed.
– Anti-diarrheals reduce the frequency of stools but do not affect the overall symptoms of IBS.
– 5HT 3 antagonists are efficacious in IBS patients with diarrhea and the quality of evidence is good. Patients need to be carefully selected, however, because potentially serious side effects include constipation and colon ischemia. Current use of alosetron is regulated by a prescribing program set forth by the FDA.
– 5HT 4 agonists are modestly effective in IBS patients with constipation and the quality of evidence is good although the possible risk of cardiovascular events associated with these agents may limit their utility. Currently, there are no 5-HT 4 receptor agonists available for use in
— Tricyclic anti-depressants and selective serotonin reuptake inhibitors have been shown to be effective in IBS patients of all subtypes. The trials generally are of good quality but the limited number of patients included in trials implies that further evidence could change the confidence in the estimate of effect and therefore the quality of evidence was graded as moderate.
– Non-absorbable antibiotics are effective, particularly in diarrhea-predominant IBS.
— The selective C-2 chloride channel activator, lubiprostone, is efficacious in constipation-predominant IBS with a moderate quality of evidence.
– Psychological therapies also may provide benefit to IBS patients although the quality of evidence is poor.
– While available trials of unique Chinese herbal mixtures appeared to show a benefit in IBS, it is not possible to combine these studies into a meaningful meta-analysis. Overall, any benefit of Chinese herbal therapy in IBS continues to be potentially confounded by the variable components used and their purity. Also, there are significant concerns about toxicity, especially liver failure, with use of any Chinese herbal mixture.
– A systematic review of trials of acupuncture for IBS was inconclusive. Further work is needed before any recommendations on acupuncture can be made.
– Patients often believe that certain foods exacerbate their IBS symptoms. There is, however, insufficient evidence that food allergy testing or exclusion diets are efficacious in IBS and their routine use outside a clinical trial is not recommended
New Recommendations on Diagnostic Testing in IBS
Because of the low likelihood of uncovering organic diseases, routine diagnostic testing with complete blood count, serum chemistries, thyroid function studies, stool for ova and parasites, and abdominal imaging should not be routinely performed in patients with typical IBS symptoms and no alarm features. Routine serologic screening for celiac sprue should be pursued in patients with diarrhea predominant IBS and the mixed type of IBS. Lactose breath testing can be considered when lactose maldigestion remains a concern despite dietary modification.
Currently, there are insufficient data to recommend breath testing for small intestinal bacterial overgrowth in IBS patients. Because of the low pre-test probability of Crohn’s disease, ulcerative colitis, and colonic neoplasia, routine colonic imaging is not recommended in patients under the age of 50 years with typical IBS symptoms and no alarm features. Colonoscopic imaging should be performed in IBS patients with alarm features to rule out organic diseases and in those over the age of 50 years for the purpose of colorectal cancer screening. The College recommends that African-Americans begin colorectal cancer screening at age 45. When colonoscopy is performed in patients with IBS-D, obtaining random biopsies can be considered to rule out microscopic colitis.
For the clinical gastroenterologist, IBS is one of the most commonly seen problems. IBS is characterized by abdominal discomfort associated with altered bowel function; structural and biochemical abnormalities are absent. The pathophysiology of IBS is multi-factorial. Individual symptoms have limited accuracy for diagnosing IBS and the disorder is considered as a symptom complex.
IBS Prevalence and Burden of Illness
– IBS is a prevalent and expensive condition that can significantly impair health related quality of life (HRQOL) and reduce work productivity.
– Epidemiologic studies suggest that 7-10% of people in the general population have IBS worldwide. Community-based studies indicate that IBS-D and IBS-M subtypes are more prevalent than IBS-C, and that switching among subtype groups may occur over time.
– IBS is 1.5 times more common in women than in men.
– IBS is more common in lower socioeconomic groups and more commonly diagnosed in patients younger than 50 years.
– IBS patients make more visits to their physicians, undergo more diagnostic tests, are prescribed more medications, miss more workdays, have lower work productivity, are hospitalized more frequently, and account for greater overall direct costs than patients without IBS.
– Resource utilization is highest in patients with severe symptoms, and poorer HRQOL.
ACG IBS Expert Task Force
– Statistician-Epidemiologist, Paul Moayyedi, B.Sc., M.B., Ch.B., Ph.D., M.P.H., FRCP (
SOURCE American College of Gastroenterology