radiographic appearances of toxic megacolon
Last reviewed 01/2018
The appearance of a toxic megacolon on plain abdominal radiographs is characterised by:
- dilatation of the lumen from 6-15 cm
- the most common sites of dilatation are the right and transverse colons
- less common sites are the left and sigmoid colons and the rectum
- there is thickening of the colonic wall with disruption of the normal haustral pattern
- there may be multiple air-fluid levels