Bosman M, Elsenbruch S, Corsetti M, et al. - High placebo response rates are linked to clinical trials for irritable bowel syndrome, so this study was carried out to distinguish the degree of the placebo response and factors contributing to this occurrence. A systematic review and meta-analysis were conducted to a search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials between April 1, 1959 and April 30, 2020. For this analysis, researchers enrolled, of the 6,863 publications identified, 70 articles describing 73 randomized controlled trials. The results demonstrate that more than a quarter of patients with irritable bowel syndrome had a placebo response in terms of global improvement, with multiple linked moderators. Future trials should apply a run-in period of at least 2 weeks and a dose once or twice a day is recommended to minimize the placebo response rate.