A case of sigmoid volvulus with classical bird's beak sign

Dr Hei Yi Wong, at Prince of Wales Hospital, Hong Kong, China and colleagues have reported a case of sigmoid volvulus with classical coffee-bean sign and bird's beak sign. The case has appeared in NEJM.

Sigmoid volvulus is a cause of large bowel obstruction and occurs when the sigmoid colon twists on its mesentery, the sigmoid mesocolon. It accounts for ~5% of all large bowel obstructions, with ~60% of intestinal volvulus involving the sigmoid colon. It is more common in the elderly although can occur in any age group.

The symptoms are that of a large bowel obstruction: constipation, abdominal bloating, nausea and/or vomiting and the onset may be acute or chronic. Abdominal radiographs will show a large, dilated loop of the colon, often with a few air-fluid levels. Specific signs include:

• coffee bean sign


• Frimann-Dahl sign - three dense lines converge towards the site of obstruction


• absent rectal gas

According to history, a 12-year-old girl presented with a 1-week history of constipation with one episode of vomiting. In the beginning, she had generalized abdominal pain but after admission, she reported having intermittent bilateral loin pain.

Courtesy NEJM

She had no history of preexisting gastrointestinal disturbances. On physical examination, the abdomen was distended but soft with an empty rectum. The supine abdominal radiograph showed a large bowel dilatation, called the coffee-bean sign, with a cleft in the center (arrows) representing torsion of the sigmoid mesentery.

Insertion of a rectal tube released a large volume of gas and a small amount of mucus. The contrast enema radiograph identified the bird's beak–like abrupt transition (arrows) at the level of the twist in the sigmoid lumen, confirming the volvulus.

On laparotomy, a redundant segment of sigmoid colon measuring 45 cm in length and 15 cm at its widest diameter was resected. The patient's postoperative recovery was unremarkable. Sigmoid volvulus is an important cause of colon obstruction in adults but is rare in healthy children.