Incidence of inflammatory bowel disease in Iceland 1995 - 2009. A nationwide population-based study

Objective. We analyzed the incidence of inflammatory bowel disease (IBD) in Iceland for the period 1995-2009. Material and methods. New cases of ulcerative colitis (UC) and Crohn's disease (CD) were retrieved by thorough review of all small and large intestinal pathology reports with any type of inflammation from all the pathology departments in Iceland for the period 1995-2009. All suspicious new cases of IBD were then scrutinized retrospectively by examination of their clinical records. Results. A total of 1175 cases of IBD were diagnosed, 884 UC, 279 CD and 12 IBD unclassified. The crude annual incidence of UC was 20.5/100,000, increasing from 18.1 the first 5-year period to 22.1 the last 5-year period. The crude annual incidence of CD was 6.5/100,000, 6.7 the first 5-year period and 6.6 the last 5-year period. Conclusions. This study shows statistically significant increase in the incidence of UC during the study period. The incidence of CD has however remained stable.