Inflammatory bowel disease: one condition or two?

Demographic data obtained from epidemiological studies of Crohn’s disease and ulcerative proctocolitis in Regio Leiden (Leiden health care region) were compared. Ulcerative colitis (6.8 cases/105 population/year) had an incidence almost twice that of Crohn’s disease (3.9/10Vyear; p 5; 95% confidence interval = 35–195) were found. This difference was significance (p