Relationship between overactive bladder and irritable bowel syndrome: a large-scale internet survey in Japan using the overactive bladder symptom score and Rome III criteria

Objective To investigate the association between overactive bladder (OAB) and irritable bowel syndrome (IBS) by using an internet-based survey in Japan. Subjects and Methods Questionnaires were sent via the internet to Japanese adults. The overactive bladder symptom score was used for screening OAB, and the Japanese version of the Rome III criteria for the diagnosis of IBS was used for screening this syndrome. Results The overall prevalence of OAB and IBS was 9.3% and 21.2%, respectively. Among the subjects with OAB, 33.3% had concurrent IBS. The prevalence of OAB among men was 9.7% and among women it was 8.9%, while 18.6% of men and 23.9% of women had IBS. Concurrent IBS was noted in 32.0% of men and 34.8% of women with OAB. Conclusion Taking into account a high rate of concurrent IBS in patients with OAB, it seems to be important for physicians to assess the defaecation habits of patients when diagnosing and treating OAB.