Prospective evaluation of formalin therapy for radiation proctitis

Radiation proctitis is a troublesome complication of radiation therapy for as many as 75% of patients after pelvic irradiation. Five percent progress to chronic radiation proctitis complicated by telangiectasias and hemorrhage. The utility of formalin rectal instillation for treatment of bleeding is prospectively evaluated in this study.

Eleven patients (9 male, 2 female) with rectal bleeding after pelvic irradiation were treated with formalin therapy. In a single treatment, 4% formalin was instilled into the rectum in four separate 20-cc aliquots with total mucosal contact time of approximately 15 minutes. Patients were initially evaluated at 7 to 10 days and 1 month postoperatively and assessed for bleeding.

All patients presented with rectal bleeding. Twenty-seven percent required transfusion. Thirty-six percent had failed other previous therapy. In follow-up of 3 to 64 months, 100% had initial success with cessation of bleeding. Three patients had recurrent bleeding; none required transfusion. One patient required repeat formalin instillation, with no further bleeding at 3 months follow-up.

Local rectal instillation of 4% formalin is an efficacious therapy for treatment of radiation-induced lower gastrointestinal bleeding.