A previously healthy 12-year-old boy presented with abdominal pain and clinical and laboratory features highly suggestive of diabetic ketoacidosis. When his blood glucose plummeted and his urinary ketones disappeared within the first hour of insulin therapy, while his abdominal pain, acidosis and hemodynamic status failed to improve despite vigorous fluid resuscitation, the diagnosis of diabetic ketoacidosis was questioned. At laparotomy, gangrenous, hugely dilated large bowel was found, requiring a subtotal colectomy from the cecum to the sigmoid colon; leaving the patient with an ileostomy. The child survived a complicated postoperative course and is currently doing well.