Anal canal stenosis and pseudo-obstruction

Mechanical large bowel obstruction and pseudo-obstruction can be difficult to differentiate because clinical symptoms and signs are often misleading. Although plain abdominal radiographs showing diffuse gaseous distension, no shut-off point and gas in the rectum are very suggestive of pseudo-obstruction, incomplete clinical examination with over-reliance on the abdominal radiographs may lead to large bowel mechanical obstruction being misdiagnosed as pseudo-obstruction. We report a rare case of large bowel obstruction occurring secondary to anal canal stenosis.