Clustering of Crohn's disease in a Cotswold village.

The first large cluster of patients with Crohn's disease, identified in the parish of Blockley, Gloucestershire is reported. Twelve patients with Crohn's disease have been identified of whom only two (a father and daughter) are known to be related. The age and sex distribution and macroscopic site of disease at diagnosis is similar to that expected in an unselected series. The identification of such a cluster suggests that environmental factors may be important in pathogenesis.