Objectives: No previous reports have shown an association between location of diverticular disease (DD) and the irritable bowel syndrome (IBS).
Methods: We included 1,009 consecutive patients undergoing total colonoscopy in seven centers in Japan from June 2013 to September 2013. IBS was diagnosed using Rome III criteria, and diverticulosis was diagnosed by colonoscopy with transparent soft-short-hood. Left-sided colon was defined as sigmoid colon, descending colon, and rectum. Right-sided colon was defined as cecum, ascending colon, and transverse colon. We divided the patients into IBS and non-IBS groups and compared characteristics.
Results: Patient characteristics included mean age, 64.2±12.9 years and male:female ratio, 1.62:1. Right-sided DD was identified in 21.6% of subjects. Left-sided and bilateral DD was identified in 6.6 and 12.0% of subjects, respectively. IBS was observed in 7.5% of subjects. Multiple logistic regression analysis showed left-sided DD (odds ratio, 3.1; 95% confidence interval (CI): 1.4-7.1; P=0.0060) and bilateral DD (odds ratio, 2.6; 95% CI, 1.3-5.2; P=0.0070) were independent risk factors for IBS. Right-sided DD was not a risk factor for IBS.
Conclusions: Our data showed that the presence of left-sided and bilateral DD, but not right-sided disease, was associated with a higher risk of IBS, indicating that differences in pathological factors caused by the location of the DD are important in the development of IBS. Clarifying the specific changes associated with left-sided DD could provide a better understanding of the pathogenic mechanisms of IBS (Trial registration # R000012739).