Sir:

A previously healthy 20-year-old male presents with a several week history of recurrent, sudden onset abdominal distention, obstipation and emesis. He reports that previous episodes resolved spontaneously and he did not seek medical attention. On this occasion, his symptoms regressed while in the Emergency Department. His clinical examination, blood work and abdominal radiographs were unremarkable. Upon being transferred to the Radiology Department for an abdominal CT scan, the patient developed a recurrence of his symptoms with significant abdominal distention. The CT demonstrated a dramatic ‘bent inner tube' or ‘omega sign' (Figure 1) and the characteristic mesenteric ‘whorl' (Figure 2, arrow) of sigmoid volvulus. The patient underwent successful decompressive flexible sigmoidoscopy. He initially refused operative intervention and was discharged. The patient soon returned with recurrent volvulus that was again decompressed and followed by sigmoid colectomy on the same admission. Unfortunately, the patient developed an anastamotic leak in the first postoperative week. This was treated with exploration, suture repair of the leak, and diverting loop transverse colostomy. The patient recovered from this procedure and was well at two-months follow-up. He will be scheduled for elective closure of his colostomy in the near future.

Sigmoid volvulus accounts for two thirds of colonic volvulus and is typically encountered in the elderly, institutionalized, or neuropsychiatric population. It is a distinctly rare cause of intestinal obstruction in the otherwise healthy North American individual but should be considered in patients with characteristic clinical and radiographic findings.

Figure 1

Figure 1: Coronal computed tomography image showing the ‘bent inner tube' or ‘omega' sign associated with sigmoid volvulus

Figure 2

Figure 2: Coronal computed tomography image showing the characteristic mesenteric ‘whorl' (arrow) associated with sigmoid volvulus.