Persistent hypoglycemia in a child with a gastrocolic fistula--an unexpected presentation of leucine-sensitive hypoglycemia.

Leucine-hypersensitive hypoglycemia is a rare clinical entity that is usually diagnosed after an exhaustive search for other causes of hypoglycemia. In nonsurgical patients, an imbalance between metabolic demands and gluconeogenesis are most frequently responsible for recurrent symptomatic hypoglycemia. In the postoperative patient, hypoglycemia more commonly results from inadequate energy intake or malabsorption from functional or anatomical abnormalities. Presented here is an unusual case of a child who was initially diagnosed with postoperative gastrocolic fistula and dumping syndrome as the cause of hypoglycemia but later found to have leucine-hypersensitive hypoglycemia.