The thyroid in ulverative colitis and Crohn's disease. II. Thyroid enlargement and hyperthyroidism in ulcerative colitis.

The frequency of thyroid disease has been surveyed in 300 patients with ulcerative colitis (UC) and 600 controls. The controls were drawn from visitors to the general medical wards of the Radcliffe Infirmary and were matched for age and sex with the UC patients. Two observers independently assessed all these subjects for thyroid enlargement of the simple goitre type. Although there were minor variations between the results obtained by the two observers, they found simple goitre in 8.7-6.3 percent among the UC patients compared with 4.3-3.3% percent among the controls; a difference which is significant. A history of thyrotoxicosis was obtained in 3.7 percent of the UC patients compared with 0.8 percent of the controls (p greater than 0.01). In more than half of the UC patients with a history of hyperthyroidism, the hyperthyroidism occurred years before the onset of the colitis. It is therefore highly unlikely that hyperthyroidism is a complication of the colitismpossible reasons for the association of the two diseases are discussed but it is concluded that no satisfactory explanation exists at present.