Application of 10 percent formalin for the treatment of radiation-induced hemorrhagic proctitis.

PURPOSE Rectal instillation of 4 percent formalin solution has been described as a successful treatment for hemorrhagic radiation proctitis recalcitrant to medical treatment. We present our experience with a new method of treatment involving the topical application of 10 percent buffered formalin, which is well tolerated and suitable for office use. METHODS Patients with marked or refractory rectal bleeding and clinical features consistent with radiation proctitis were reviewed. Treatment involved direct application of a 10 percent buffered formalin solution to the affected mucosa using a 16-inch cotton tip applicator applied through a proctoscope in the office setting. RESULTS A total of 100 patients with a mean age of 75 (range, 49-91) years were followed for 18 (range, 1-79) months. The interval from radiation exposure to formalin treatment was 21 months. Overall, 93 percent of patients had cessation of bleeding after an average of 3.5 formalin applications at two-week to four-week intervals. Patients with severe (Grade 3) proctitis and those taking aspirin required an average of 1.5 additional treatments. A total of eight patients rebled at a mean of 24 months from treatment; however, all responded to further applications of formalin. Three patients complained of anal pain and one experienced dizziness postprocedure for a complication rate of 1.1 percent. CONCLUSIONS We present a simple, cost-effective, and well-tolerated method of controlling hemorrhagic radiation proctitis. It is performed by using materials readily available in the office of a colon and rectal surgeon, eliminating the need for bowel preparation, anesthesia, or a surgical suite.