Epidemiology of Inflammatory Bowel Disease in the Songpa-Kangdong District, Seoul, Korea.

Inclusion Criteria: * Definite cases of CD and UC Patients are diagnosed with CD if they meet at least 2 of the following criteria: 1. clinical history of abdominal pain, weight loss, malaise, diarrhea, and/or rectal bleeding 2. endoscopic findings of mucosal cobblestoning, linear ulceration, skip areas, or perianal disease 3. radiologic findings of stricture, fistula, mucosal cobblestoning, or ulceration 4. macroscopic appearance of bowel wall induration, mesenteric lymphadenopathy, and "creeping fat" at laparotomy 5. pathologic findings of transmural inflammation and/or epithelioid granulomas Only patients who meet these criteria for at least 2 months are included. Patients are diagnosed with UC only if all 3 of the following criteria are present 1. a typical history of diarrhea or blood and pus or both in the stool for longer than 4 weeks 2. a typical sigmoidoscopic or colonoscopic picture with diffusely granular, friable, or ulcerated mucosa without rectal sparing or skip lesions or radiological signs of characteristic continuous granular or ulcerated mucosa 3. characteristic histopathological signs of inflammation on biopsy Exclusion Criteria: * IBD unclassified * Ethnic groups other than Korean