Inflammatory bowel disease (IBD) is associated with lifetime morbidity and the onset of disease frequently occurs in early life. Although IBD manifests throughout all ethnic groups, there has been marked heterogeneity in its incidence, prevalence, manifestation, and outcome. We sought to study the incidence, prevalence, and survival of ulcerative colitis (UC) and to examine the evolution and prognostic predictors of Crohn's disease (CD) and UC among Hong Kong Chinese. A total of 4 studies were performed to address these issues. One longitudinal cohort study examined the incidence, prevalence, survival and phenotypic changes of UC. Two other longitudinal cohort studies evaluated the phenotypic evolution of CD. One of them specifically compared the course of disease between patients with and patients without upper gastrointestinal tract phenotype. The final retrospective study identified clinical factors that predicted the occurrence of corticosteroid dependency and refractoriness in patients with IBD. The annual age-standardized incidence rate and point prevalence of UC per 100,000 Hong Kong Chinese in 2006 were 2.1 (95% CI: 1.1-3.7) and 26.5 (95% CI: 22.6-30.9), respectively. Incidence of UC has increased 6 times over the past two decades. The overall survival of UC patients was similar to the expected survival of the Hong Kong population. Phenotypic changes in CD also occurred in Chinese patients in the same way as the white patients with respect to disease behavior, though at a slower rate. Similar to the white CD patients, the location of disease remained relatively stable over the course of disease. Chinese CD patients had more upper gastrointestinal tract phenotype which predicted the need of surgery and subsequent hospitalization. On the other hand, the rate of proximal extension of UC was less than 25% after 10 years. In CD, thrombocytosis predicted, whereas colonic disease negatively predicted corticosteroid dependency. Stricturing CD was associated with corticosteroid refractoriness. In UC, thrombocytosis and extensive colitis predicted corticosteroid dependency, whereas anemia predicted corticosteroid-refractory disease. The results of these studies are important in the planning of health service and they also assist in the formulation of treatment strategy. / Chow, Kai Lai. / "May 2009." / Advisers: Francis KL Chan; Joseph JY Sung. / Source: Dissertation Abstracts International, Volume: 72-01, Section: B, page: . / Thesis (M.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 193-235). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.