Crohn's disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases (IBD) that result in considerable morbidity and impaired quality of life. Although IBD is ubiquitous, heterogeneity in incidence is noted geographically and among different ethnicities, presumably due to genetic and environmental factors. The incidence and prevalence of IBD has plateaued in many Western countries but are increasing in developing nations. There is a lack of data on IBD pertaining to the Chinese population. / Studies were conducted to determine the characteristics of IBD in the Chinese population. The incidence of IBD in the Chinese population is a fifth to a tenth of Western societies but has risen sharply over the past decade. Several distinct demographic and phenotypic features were noted in the Chinese IBD population. Genetically, Chinese CD patients do not harbour the NOD2/CARD15 polymorphisms unlike Caucasian CD subjects. ANCA and ASCA are serologic markers that are highly specific for UC and CD respectively in the Chinese but ANCA sensitivity in Chinese UC is significantly lower than in Caucasian UC, while quantitative IgG ASCA (and not IgA) is a moderately sensitive test for CD. These markers are useful in differentiating UC from CD. A Chinese translation of the Inflammatory Bowel Disease Questionnaire (IBDQ) was developed and validated to be reliable, sensitive to change and reproducible. A prospective cross-sectional survey of the disease-related knowledge of Chinese and Australian IBD patients identified a low level of IBD-knowledge but with a similar quality of life as Caucasians with IBD. There was a similar but high rate of use of complementary alternative medicines in both populations. / These studies were instrumental in: describing IBD in the Chinese population; developing a Chinese IBD database; acquiring techniques of investigating genetic polymorphisms and ASCA serology; devising the Chinese IBDQ to open up IBD trials to Hong Kong; and identifying knowledge deficiencies to help plan a targeted education programme. / Leong Rupert Wing-Loong. / Adviser: Joseph J.Y. Sung. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (M.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references. / 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, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.