Familial association between coeliac disease and ulcerative colitis: preliminary communication.

One hundred and twenty patients who were members of the Nottinghamshire Coeliac Group completed a questionnaire about the occurrence of coeliac disease, ulcerative colitis and Crohn's disease amongst first-degree relatives. Siblings were at a 20-fold risk of developing coeliac disease and a 15-fold risk of developing ulcerative colitis, and significantly increased risks for these two conditions were also seen in other family members. The relatives of patients with coeliac disease are at increased risk not only of developing coeliac disease but also ulcerative colitis. This provides further support for a possible role of a dietary allergen in the development of ulcerative colitis.