Clinical Presentation

A 44-year-old woman presents with abdominal pain and distension.

(A) Abdominal radiograph shows colonic dilatation (large arrowhead) terminating in the pelvis (arrow) and multiple air-filled ileal loops that are abnormal in caliber (small arrowhead). (B) Single-contrast barium enema shows an irregularly marginated stricture (arrows) of the rectosigmoid colon. (C) Pelvic computed tomography (CT) shows marked attenuation of the rectal lumen (arrow) leading to a critical stenosis (arrowhead) due to a circumferential infiltrating soft-tissue mass.

Differential Diagnosis

• Rectosigmoid carcinoma: This is the most worrisome diagnosis and should be at the top of the list for distal colonic obstruction.

• Intraluminal material: Impacted feces or foreign bodies may cause distal obstruction. Fecal impaction is typically bubbly, but not always.

• Inflammation or infection: