[Epidemiologic aspects of ulcerative colitis in Japan--comparison with other countries]

In this review, recent data of epidemiological characteristics of ulcerative colitis in Japan were presented, and compared to those of other areas in the world. Hospital-based investigation in 1991 revealed that the prevalence was 18.12/100,000, and the incidence was 1.95/100,000. The incidence in Japan is much lower than in Europe and in north America where strikingly higher incidence(7-14/100,000) have been reported. There were not any differences in male/female ratio and age of onset between Japan and Western countries. While the incidence in Western countries has reported to be stable, the value increased greatly during the past 25-year period in Japan.