Details
Rectum resection, with previous history of subtotal colectomy.
Diversion colitis occurs in a distal colonic segment isolated from intraluminal fecal transit. This most commonly occurs in the context of a diverted segment of colon, such as a Hartmann pouch. Cell injury is due to nutritional deprivation, in particular, short-chain fatty acids. Patients are sometimes asymptomatic but often present with abdominal pain, rectal discomfort and tenesmus.
This section demonstrates most typical features; it is a section of large bowel with chronic lymphoplasmacytic inflammation in the lamina propria and mucosal architectural distortion. Mucosal follicular lymphoid hyperplasia is abundant. Active crypt inflammation, erosions and ulcerations are present. Paneth cell metaplasia is a frequent finding and is due to the chronic nature of the injury.
See related content for references:
1) Apslund, S., et al. Dis Colon Rectum. 2002 Sep;45(9):1206-13.
2) Haque, S., et al. Hum Pathol. 1993 Feb;24(2):211-9.