Changing patterns in epidemiology of Crohn's disease.

Abstract The frequency of admissions for Crohn's disease in England and Wales increased almost threefold between 1958 and 1971, while the incidence of Crohn's disease in the Nottingham area for the same period increased fivefold. Although part of the change is probably accounted for by improved diagnosis, it seems unlikely that this completely explains the rise. During the same period admissions for ulcerative colitis in England and Wales increased only slightly. Comparison of prevalence data suggests that disease frequency is broadly equivalent in several parts of northern Europe, and further information is needed, especially from areas where the disease is rare, if useful aetiological hypotheses are to be derived.