Definition:
Diversion colitis is a nonspecific inflammatory disorder that occurs in segments of the colon and rectum that are diverted from the fecal stream by surgery
Epidemiology
Unknown
Pathophysiology
Deficiency of short-chain fatty acids (SCFAs) and other luminal nutrients in colonocytes in the diverted segment of the colon. It is hypothesized that the lack of these compounds or interference with their metabolism by alterations in gut flora may have a role in the development of colitis.
Clinical presentation
- <50% of patients with histologic evidence of diversion colitis have symptoms
- In patients who are symptomatic, the onset usually occurs 3 to 36 months after colonic diversion
- Tenesmus, urgency, bloody and/or mucus discharge, abdominal pain, and pelvic pain or pressure
Complications
- Stricture
- Bezoar - due to accumulation of mucus materials
- Colorectal cancer - chronic inflammation. Surveillance for CRC in the diverted segment is not required unless the underlying condition for which the surgery was performed is associated with an increased risk of CRC
Diagnosis
- Endoscopy findings — Endoscopic features of diversion colitis are nonspecific and include erythema, friability, edema, mucus plugs, and granularity of the colorectal mucosa. In more severe cases, patients may have ulcers, nodularity, edema, or inflammatory and filiform polyps, strictures, or fecal bezoars
- Histopathology — Histopathologic features of diversion colitis are not diagnostic, but biopsies of the colon are necessary to exclude other causes of colitis. The most common pathologic features of diversion colitis include expanded lymphoid aggregates and inflammation in the lamina propria with lymphocytes and plasma cells and regenerative gland and mucin-depleted glands