The entire large bowel is dilated down into the pelvis.
Dilated loops of small bowel are also visible. This indicates incompetence of the ileocaecal valve, which allows gas to build up in the small bowel as well as in the large bowel.
The obstruction was found to be due to an obstructing tumour of the sigmoid colon which was treated using a colonic stent (see image below).
A colonic stent has been inserted and the colon is no longer dilated.
Colonic stents are placed in the emergency setting under radiological guidance. This allows patients to recover from the acute effects of obstruction before definitive surgery is performed.
This image demonstrates dilatation of the colon down to an area where there is conspicuous narrowing of the bowel and an area of increased soft tissue density.
This was found to be a tumour of the descending colon.
Bowel obstruction can be complete or partial. Gas in the rectum, as seen in this case, is a feature of incomplete obstruction.
If bowel obstruction is seen on an abdominal X-ray then a CT is indicated to help plan treatment - see image below.