Background
Irritable bowel syndrome (IBS) is a functional bowel disease characterized by abdominal pain or discomfort associated with altered bowel habits. Several clinical studies have demonstrated the effectiveness of acupuncture and moxibustion for IBS. Many systematic reviews of acupuncture and moxibustion for IBS have been published in recent years, but their results are not entirely consistent.

Objective
To evaluate the methodological, reporting, and evidence quality of systematic reviews of acupuncture and moxibustion for IBS.

Search strategy
Systematic reviews of acupuncture and moxibustion for IBS published before February 20, 2023 were searched in eight databases: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang Data, VIP Database for Chinese Technical Periodicals, and China Biology Medicine. The keywords used for literature search were acupuncture, moxibustion, systematic review, meta-analysis, and irritable bowel syndrome.

Inclusion criteria
Systematic reviews and meta-analyses of randomized controlled trials of acupuncture and moxibustion for IBS were included.

Data extraction and analysis
Relevant information was independently extracted by two investigators. The A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2), Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020), and Grading of Recommendations Assessment, Development and Evaluation (GRADE) were used to evaluate the methodological quality, reporting quality and evidence quality, respectively.

Results
A total of 342 studies were retrieved and 15 systematic reviews were included. The results of AMSTAR 2 showed low methodological quality in 2 studies and very low methodological quality in the remaining 13 studies, with main issues being failure to register a protocol, incomplete search strategy, not providing a list of excluded studies, incomplete consideration of the risk of bias in the included studies, and a failure to assess the publication bias. The results of PRISMA 2020 showed seriously deficient reporting quality of 2 studies, somewhat deficient reporting quality of 12 studies, and relatively complete reporting quality of 1 study, with the main problems being lack of a complete search strategy, non-availability of a list of excluded studies with justification for their exclusion, not conducting heterogeneity and sensitivity analyses, not evaluating the credibility of the evidence, and not registering the protocol. The results of GRADE showed that the quality of the evidence is low or very low.

Conclusion
Most included systematic reviews interpreted findings to suggest that acupuncture and moxibustion have benefits for IBS. However, there is a need to improve the methodological, reporting and evidence quality of the systematic reviews. Larger, multicenter, rigorously designed randomized controlled trials and high-quality systematic reviews are required to obtain more robust evidence.

Key words: Irritable bowel syndrome, Acupuncture, Moxibustion, Umbrella systematic review, Systematic review