Prevalence of irritable bowel syndrome and its association with colorectal cancer: a systematic review and meta-analysis.

Background: This study evaluates the risk of colorectal cancer (CRC) in patients with Irritable Bowel Syndrome (IBS).

Methods: A literature search was performed on MEDLINE, EMBASE, SCOPUS, and Google Scholar from inception to 31st January 2020 without any limitations on article type or language for studies reporting data on CRC on patients with IBS. A meta-analysis was performed to estimate the prevalence of CRC among patients with IBS. Data extraction was according to the PRISMA guidelines. The quality of the included studies was assessed according to the Newcastle Ottawa Scale.

Results: Twenty-one articles were eligible for data extraction and quantitative analysis. Of them, 11 were included in the meta-analysis (IBS n = 284 366, no-IBS n = 8 390 509). The pooled prevalence of CRC in patients with IBS was 0.96% (95% CI-0.184%-2.344%). The prevalence was lowest in the constipation-predominant IBS (pooled prevalence 1.126%. Patients with IBS-D and IBS-U had an equal pooled prevalence of CRC (2.49%). Eleven studies compared the prevalence of CRC in patients with IBS with a control population. The pooled OR was 2.8 (CI 2.305-3.294).

Conclusions: There was an increased risk of CRC among patients diagnosed with IBS, primarily in the first year after IBS diagnosis.

Registration: The review was registered on PROSPERO (CRD42021236707).