Crohn's disease in northern Ireland - A retrospective survey of 159 cases.

A RETROSPECTIVE survey of Crohn's disease in a circumscribed population was carried out to determine the incidence of the disease in Northern Ireland and to compare the findings with previous regional studies in the British Isles. One hundred and fifty-nine cases were selected by strict criteria for detailed examination. Epidemiological data is presented which demonstrates that Crohn's disease has a similar distribution in this population to that seen in other regions. The crude annual incidence rate of 1.3 per 100,000 lies in the lower half of the range of published figures.Remarkable findings were the higher incidence of Crohn's disease with increasing age, particularly in females and the significantly higher incidence in the urban population.