Table 2.

Comparison of acute vs chronic radiation proctitis

	Acute proctitis	Chronic proctitis
Symptom development	≤ 3 mo from start of radiation	> 3 mo from start of radiation to years later
Incidence	Common (50%-100%)	Less common (2%-20%)
Common symptoms	Diarrhea, urgency, pain	Rectal bleeding
Rare symptoms	Significant rectal bleeding	Stricture, obstruction, fistula
Histopathology	Epithelial cell depletion with inflammatory infiltrate	Small vessel changes without inflammatory infiltrate
Treatment	Conservative, medical	Conservative, medical, endoscopic, surgical