Crohn's Disease Clinical Network and Cohort (CONNECT) Study: The First Step Toward Nationwide Multicenter Research of Crohn's Disease in Korea

of population-based cohort studies. Most of the currently available data comes from single-center, hospital-based studies. Several important cohort studies conducted in Western Europe and America have described the clinical course of CD. Consequently, investigators are becoming aware of the need for a cohort study of CD in Korea. Moreover, genetic or biomarker studies need blood or tissue specimens from a large number of patients, which should be collected together with accurate, matched clinical data. This highlights the urgent need for a nationwide collection of well-defined clinical characteristics of Korean CD patients and their biological specimens.