Volvulus of the sigmoid colon is rare in children although it is a common cause of large bowel obstruction in elderly people. We report a case of sigmoid volvulus in a 14-year-old girl with intellectual disability. She had a 1-year history of chronic diarrhea despite supportive treatment. She was brought to the emergency department because of intermittent abdominal pain associated with vomiting of bile and passage of bloody stools. A plain X-ray showed dilated bowel loops. A contrast-enhanced computed tomography (CT) scan showed both limbs of the distended loop tapering in size and forming a round soft-tissue mass with whirled configuration in the left colonic compartment.Preoperatively, volvulus was suspected. Exploratory laparotomy disclosed a markedly distended sigmoid colon packed with fecal material and a counterclockwise rotation of 720 degrees with strangulating gangrene. The volvulus was untwisted, and a 65-cm segmental resection of the colon and primary anastomosis were performed. The patient was discharged on the 19 th day following an uneventful postoperative course. We believe that a contrastenhanced CT scan is a useful tool in the diagnosis of sigmoid volvulus.