Functional bowel disorders among bariatric surgery candidates before and after surgery: A prospective cohort study

Background: Functional bowel disorders (FBDs), including irritable bowel syndrome (IBS), are common worldwide. Recently, increasingly many bariatric surgical procedures have been performed in response to rising obesity rates. However, data on the association between FBDs and bariatric surgery are scarce. We examined the prevalence of FBDs among candidates for bariatric surgery and prospectively investigated the association between FBDs and bariatric surgery. Methods: This prospective cohort study included 112 bariatric surgery candidates at the Tel Aviv Medical Center from 2019 to 2020. Before and after surgery, patients completed the Rome III questionnaire. Data regarding demographics, socioeconomic status, and gastrointestinal symptoms were recorded. The rates of FBDs—IBS, functional constipation (FC), functional diarrhea (FDi), and unspecified functional bowel disorder (UFBD)—were then compared from before surgery to 6 months after the procedure. Results: Of 112 candidates with obesity at baseline, 68 underwent surgery and completed the postoperative questionnaire. Overall, the respective prevalence rates of FBDs, IBS, FC, FDi, and UFBD were 37.5%, 2.7%, 17.9%, 5.4%, and 11.6%. Female sex and single status were particularly common among patients with FBDs, whereas divorced status was more frequent in the group without FBDs. However, these factors were not independently associated with FBD presence upon multivariable analysis. IBS was more prevalent after surgery than before (8.8% vs. 1.5%, P = 0.06), but FBDs in general did not share this trend (44.1% vs. 36.8%, P = 0.44). Conclusion: Bariatric surgery appears to increase the risk of developing IBS, while not impacting the overall risk of FBDs.