Severe hyponatremia and repeated intestinal resections for intestinal dysmotility mimicking congenital aganglionic megacolon due to delay in the diagnosis of congenital hypothyroidism.

Congenital hypothyroidism (CH) may present with nonspecific signs and symptoms, though, majority of infants can be asymptomatic. Therefore, understimation and delay in diagnosis may result in severe complications. A 5-month-old female admitted to our clinic with the history of repeated surgical operations due to the diagnosis of congenital aganglionic megacolon. Investigations performed in our clinic revealed the diagnosis of congenital (primary) hypothyroidism due to thyroid agenesis. Histopathologic evaluation of previously resected colon sample revealed normal ganglionic cell included colon. During follow-up she developed severe hyponatremia with a plasma sodium level of 106 mEq/L. Eunatremia was maintained following achievement of euthyroid state. In conclusion, since presenting symptoms can be variable and nonspecific, hypotyhroidism should be kept in mind in the differential diagnosis of patients with persistent abdominal distention mimicking aganglionic megacolon and severe hyponatremia of unknown origin.