Hypothyroidism and megacolon

: A 71 years old woman, affected by ischemic heart disease from the age of 50 and by chronic constipation was admitted to the emergency department for drowsiness, intense dyspnea and acute abdominal distension. Laparotomy evidenced a megacolon. Because of the age and sex of the patient the congenital form of the megacolon was ruled out. No one of the more common causes of megacolon was recognized, but a severe hypothyroldism and Hashimoto's thyroiditis was discovered. Treatment with levothyroxine caused a progressive improvement of the general condition of the patient and of the megacolon so that the authors hypothesize that the intestinal pseudo-occlusion was caused by the hypothyroidism. In this paper the authors make a thorough analysis of the literature about the association between hypothyroidism and megacolon. Although many hypothesis have been put forward about the possible pathogenetic association between these two diseases, until now no definitive result has been reached. The authors, moreover, hypothesize that the pleural and pericardial effusion and the peculiar metabolic state characterized by plasma hyponatremia and hyposmolarity, with a constant urinary hyperosmolarity, were also caused by hypothyroidism; in fact the clinical and metabolic conditions improved after levothyroxine therapy. In the end the authors discuss if it is preferable to use tetraiodothyronine or triIodothyronine for the treatment of intense hypothyroidism in a patient in critical clinical state.