Large bowel obstruction is a key surgical pathology, one which both clinicians and radiologists working out of hours should be at capable of diagnosing and managing.

A high proportion are due to the first presentation of a sigmoid colorectal carcinoma.   Complicated diverticular disease with stricture formation is another common cause.

This was a short stenosing rectosigmoid junction tumor causing a high grade large bowel obstruction.  The right side of the colon is suggestive of imminent perforation.