Comorbid irritable bowel syndrome symptoms and headache have greater association with anxiety than depression: Annual health check-up survey results

High rates of co-existing irritable bowel syndrome (IBS) and headache have been reported in western countries. We investigated that comorbidity in individuals in Japan, along with anxiety and depression in subjects with and without IBS symptoms and/or headache. This cross-sectional study was performed from April 2012 to January 2013 at the Matsue Seikyo General Hospital Health Check Center. Questionnaires concerning symptoms related to IBS (Rome III) and headache, as well as anxiety/depression score were sent to individuals scheduled to undergo an annual health check-up, then returned during the visit and analyzed in a blinded manner. A total of 2885 individuals returned completed questionnaires and were enrolled, of whom 218 (7.6%) met the IBS criteria. The rates of co-existing headache in subjects with and without IBS symptoms were 44.0% (96/218) and 22.9% (611/2667), respectively, indicating a significantly higher rate of co-existing headache in subjects with as compared to without IBS (odds ratio [OR] 2.65, P < .001). Furthermore, the percentage of subjects with anxiety along with comorbid IBS symptoms and headache was significantly greater as compared to those with IBS (OR 3.01, P = .001) or headache (OR 2.41, P < .001) alone. Unlike anxiety, the percentage of subjects with depression was not significantly different among the IBS/non-headache, non-IBS/headache, and IBS/headache groups. Subjects with IBS symptoms had a higher rate of co-existing headache as compared to those without IBS. Furthermore, those with comorbid IBS symptoms and headache had a greater association with anxiety than with depression, as compared to those with only IBS or headache.