Background and aims: Multiple pharmacologic treatments are available for the management of irritable bowel syndrome (IBS), and a large body of evidence has been presented. However, the strength and credibility of the evidence have not been comprehensively evaluated. We aimed to review the systematic reviews and meta- analyses of pharmacologic treatments for IBS and evaluate the credibility of the findings.
Methods: We searched MEDLINE, Embase, and Cochrane library from inception to September 2019 for systematic reviews evaluating the effectiveness of pharmacologic treatments for IBS. We summarized relative ratios (RR), evaluated the credibility of the evidence and classified the evidence into convincing, highly suggestive, suggestive, and weak.
Results: We included 11 systematic reviews with 40 meta-analyses (330 randomized controlled trials and 86,459 participants) assessing 10 treatment categories and 2 drugs. Most of the pharmacologic treatments were significantly superior over placebo as reported by the included meta-analyses. The evidence for 5-hydroxytryptamine (5-HT)3 antagonists (RR=1.56, 95%CI: 1.43-1.71), antispasmodics (RR=1.19, 95%CI: 1.02-1.39), and alosetron (RR=1.46, 95%CI: 1.26-1.71) were highly suggestive for relieving global IBS symptoms. 5-HT4 agonists (RR= 1.26, 95%CI: 1.19-1.34) and guanylate cyclase-C (GCC) agonists (RR=1.73, 95%CI: 1.54-1.95) were found to give convincing evidence for the improvement of the responder rate. 5-HT3 antagonists (RR=1.32, 95%CI: 1.26-1.38) offered convincing evidence for relieving abdominal pain.
Conclusions: Evidence for 5-HT3 antagonists, 5-HT4 agonists and GCC agonists, antispasmodics, and alosetron were suggestive for the treatment of IBS. However, owing to the risk of bias in randomization methods, the results for GCC should be interpreted with caution.