A 13-YEAR-OLD girl entered the pediatric emergency department complaining of increasing abdominal pain. Her illness started 4 days earlier with cramping in the left iliac fossa. The cramps increased in duration and frequency. She had had no bowel movements in the last 8 days and no results from enemas.
On clinical examination, the girl was in no acute distress but was markedly overweight: 83.5 kg with a height of 155 cm. Her obesity made the clinical examination of the abdomen difficult. Palpation of the left lower quadrant was not painful but a mass could be felt. Peristaltic activity was normal. Results of rectal examination were normal and results of a radiograph of the abdomen were normal. In an attempt to visualize the colon and loosen impacted stool, a water-soluble contrast enema was performed using diatrizoate meglumine (Figure 1). Later sigmoidoscopy results were judged to be normal and showed neither obstruction