An Evidence-Based Systematic Review on the Management of Irritable Bowel Syndrome

Abstract

Section 2.1 Methodology for systematic reviews of irritable bowel syndrome therapy, levels of evidence, and grading of recommendations We have conducted a series of systematic reviews on the diagnostic criteria, the value of diagnostic tests, and the efficacy of therapy in IBS. We also performed a narrative review of the epidemiology of IBS. There have been several systematic reviews of therapy for IBS (1-5), but these either have not quantitatively combined the data into meta-analyses (1-3) or have inaccuracies in applying eligibility criteria and data extraction (4,5). We have, therefore, repeated all systematic reviews of IBS and synthesized the data where appropriate. Systematic review methodology For all reviews, we evaluated manuscripts that studied adults using any definition of IBS. This included a clinician-defined diagnosis, Manning criteria (6), the Kruis score (7), or Rome I (8), II (9), or III (10) criteria. For reviews of diagnostic tests, we included case series and case-control studies that evaluated serologic tests for celiac sprue (anti-gliadin, anti-endomysial, and tissue transglutaminase antibodies), lactose hydrogen breath tests, and tests for small bowel bacterial overgrowth (lactulose and glucose hydrogen breath test or jejunal aspirates). For reviews of therapies of IBS, we included only parallel group RCTs comparing active intervention with either placebo or no therapy. The following treatments were considered: Diet Fiber, bulking agents, and laxatives Antispasmodics and Peppermint Oil Antidiarrheal agents Antibiotic therapy Probiotic therapy 5HT3 antagonists 5HT4 agonists Selective C-2 chloride channel activators (Lubiprostone) Antidepressants Psychological therapies Herbal therapies and acupuncture Emerging therapies Subjects needed to be followed up for at least one week. The trial needed to include one or more of the following outcome measures: Global assessment of IBS cure or improvement Abdominal pain cure or improvement Global IBS symptom or abdominal pain scores Search strategy for identification of studies Medline (1966-June 2008), Embase (1988-June 2008), and the Cochrane Controlled Trials Register (Issue 2, 2008) electronic databases were searched. An example of the Medline search is given below. IBS patients were identified with the terms irritable bowel syndrome and functional diseases, colon (both as medical subject heading (MeSH) and free text terms), and IBS, spastic colon, irritable colon, and functional adj5 (adj5 is a term used by Medline for words that appear within 5 adjectives of each other) bowel (as free text terms). Studies identified from this search were combined with the following terms used to identify therapies for IBS: dietary fiber, cereals, psyllium, sterculia, karaya gum, parasympatholytics, scopolamine, trimebutine, muscarinic antagonists, and the following free text terms: bulking agent, psyllium fiber, fiber, husk, bran, ispaghula, wheat bran, spasmolytics, spasmolytic agents, antispasmodics, mebeverine, alverine, pinaverium bromide, otilonium bromide, cimetropium bromide, hyoscine butyl bromide, butylscopolamine, peppermint oil, loperamide and colpermin, serotonin antagonists, serotonin agonists, cisapride, receptors (serotonin, 5-HT3), and receptors (serotonin, 5-HT4; both as MeSH terms and free text terms), and the following free text terms: 5-HT3, 5-HT4, alosetron, cilansetron, tegaserod, and renzapride, psychotropic drugs, antidepressive agents, antidepressive agents (tricyclic), desipramine, imipramine, trimipramine, doxepin, dothiepin, nortriptyline, amitriptyline, selective serotonin re-uptake inhibitors, paroxetine, sertraline, fluoxetine, citalopram, venlafaxine, cognitive therapy, psychotherapy, behaviour therapy, relaxation techniques, and hypnosis (both as MeSH terms and free text terms), and the following free text terms: behavioral therapy, relaxation therapy, and hypnotherapy. Saccharomyces, Lactobacillus, Bifidobacterium, Escherichia coli or probiotics (MeSH and free text terms). An RCT filter was applied to the electronic searches. The searches were limited to humans. A recursive search of the bibliography of relevant articles also was conducted. DDW abstract books were hand searched between 2000 and 2008; UEGW abstract books were hand searched between 2000 and 2007. Authors of trial reports that did not give enough detail for adequate data extraction were contacted and asked to contribute full datasets. Experts in the field were contacted for leads on unpublished studies and no language restrictions were applied. Trials were assessed for risk of bias according to three characteristics: method of randomization, method of concealment of treatment allocation, and implementation of masking. In addition the of studies were according to the with a score of a and outcome data were by the and by a on was by using a were as and were to be treatment any improvement of IBS as a outcome was as the outcome this was not improvement in abdomi