Epidemiology of inflammatory bowel disease in Asia.

Studies of Asians in Asia show relatively low incidence rates for ulcerative colitis and Crohn's disease compared with North America and Europe. The prevalence of ulcerative colitis in migrant South Asians in Europe is similar to Europeans, whereas the prevalence of Crohn's disease for migrant South Asians in Europe is decreased compared with Europeans. The prevalence for both ulcerative colitis and Crohn's disease in Japan and Korea is relatively low. There are no obvious differences in age or sex distribution or rates of familial aggregation, and there are no significant differences in the clinical characteristics and natural history of ulcerative colitis and Crohn's disease in Asians compared with other racial groups with inflammatory bowel disease.