Background and Rationale: Inflammatory bowel disease (IBD) is a major burden to individuals and society. Ulcerative colitis and Crohn's disease (CD) are the 2 major inflammatory bowel diseases (IBD). They share some pathologic and clinical features but overall their pathogenesis is not resolved and diagnosis is sometimes difficult. The incidence rates range from 3.1 to 14.6 cases per 100,000 person year for Crohn's disease to 2.2 to 14.3 cases per 100,000 person years for ulcerative colitis and prevalence ranges up to 201/100,000 for Crohn's disease and up to 246/100,000 persons for ulcerative colitis.