Background: Irritable bowel syndrome (IBS) is a common disorder characterized by the recurrence of abdominal pain and changes in bowel habits. Owing to the limitations of conventional treatments, patients with IBS are often dissatisfied with the effect of treatment and have a poor quality of life. Herbal medicines (HMs) are frequently used for the treatment of IBS. This protocol was designed through an overview of systematic reviews (SRs), to investigate the safety and efficacy of HMs for treating IBS. Methods: SRs published up to May 2021 will be searched from the following 6 electronic databases: Medline (via PubMed), EMBASE, Cochrane Database of Systematic Reviews, Allied and Complementary Medicine Database, Oriental Medicine Advanced Searching Integrated System, and China National Knowledge Infrastructure database. SRs and/or meta-analyses on the use of HMs for IBS will be included in this overview. The effects of a placebo, no treatment, usual care, or conventional treatment will be compared with those of HMs. Two investigators will independently extract the data and assess the methodological and evidence quality for each main finding. The total clinical effectiveness rate will be measured as the primary outcome. Results: This overview is expected to provide data on the use of HMs for the treatment of IBS based on qualitative and quantitative syntheses of the included SR data. Conclusion: This overview will evaluate and propose the efficacy and safety of HMs for the treatment of IBS. Registration number: DOI 10.17605/OSF.IO/NT6WZ ( https://osf.io/nt6wz ).

Background: Irritable bowel syndrome (IBS) is a chronic functional bowel disorder characterized by abdominal pain or discomfort, stool irregularities, and bloating. Owing to its atypical symptoms and various mechanisms, there is no standard treatment for IBS. Gwakhyangjeonggi-san (GJS), a traditional Korean herbal medicine, has been used to treat lower intestinal abnormalities in Asia. We will systematically review randomized controlled trials (RCTs) to evaluate the efficacy and safety of GJS as a complementary treatment for IBS. Methods and analysis: Four English databases, namely, Medline (via PubMed), EMBASE, the Cochrane Central Register of Controlled Trials, and the Allied and Complementary Medicine Database, will be searched for entries up to May, 2021. Additional databases will include 5 Korean databases, 1 Chinese database, and 1 Japanese database. RCTs and quasi-RCTs will be searched for to assess the effectiveness and safety of GJS. The primary outcome measure will be the overall efficacy rate, and the secondary outcome will include data such as global symptom scores, IBS Quality of Life measurements, and adverse events. Data analysis will be performed using Review Manager Version 5.3, and the risk of bias will be assessed using the Cochrane Collaboration's risk-of-bias tool. The quality of the results will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation approach. Conclusion: This systematic review will provide evidence for the efficacy and safety of GJS for IBS. OSF registration number: DOI 10.17605/OSF.IO/V93JN ( https://osf.io/v93jn ).