Background: Our purposes were to (1) evaluate efficacy and safety of bipolar or heater probe endoscopic coagulation compared to prior medical therapy for bleeding radiation telangiectasia, and (2) consider the impact of treatments on patients' impression of their overall health and activity. Methods: Twelve months of medical management had failed in 18 men and 3 women with chronic, recurrent hematochezia and anemia after radiation treatment of pelvic malignancies. Patients had multiple rectal telangiectasias coagulated with bipolar or heater probes in a randomized, prospective study. Results: Rectal bleeding stopped within four treatment sessions. During 12 months of endoscopic versus medical therapy, severe breeding episodes diminished significantly for bipolar probe versus 12 months of prior medical therapy (75% vs 33%) and heater probe (67% vs 11%); mean hematocrits rose significantly for patients undergoing bipolar (38.2 vs 31.9) and heater probe (37.6 vs 28.4) treatments, and their impression of overall health improved. During long-term follow-up, new telangiectasias or rectal bleeding were easily controlled. No major complications resulted. Conclusions: (1) Bipolar or heater probes were safe and effective relative to medical therapy for palliation of patients with lower gastrointestinal breeding from radiation telangiectasias, and (2) ail patients improved in ability to travel and exercise and in their overall impression of their health.