Complications following formalin installation in the treatment of radiation induced proctitis.

Formalin installation has been safely and effectively used to treat refractory bleeding caused by radiation proctitis. This study evaluated the results of such treatment in terms of outcome and complications. All four patients who underwent formalin irrigation for transfusion-dependent radiation proctitis over a 15-month period were evaluated retrospectively. The procedure was performed under sedation in the operating room, with patients in the prone jack-knife position. A solution of 4% formalin was introduced in aliquots of 50 ml kept in contact with the mucosa for 30 s and then cleared away using saline irrigation; five to six aliquots were used in each session. In a fifth patient formalin-soaked gauze pads were applied directly to the injured mucosa. At a mean follow-up of 18 months (range 6-26) two patients had repeat episodes of bleeding, one underwent successful repeat irrigation, and the other refused further treatment. One patient suffered from severe anococcygeal pain and worsening of incontinence after the procedure. The pain was treated with lidocaine ointment and sitz baths with partial success. Another patient developed severe formalin-induced colitis 5 days after the procedure, which required intravenous antibiotics and hydration. Formalin installation may be effective in controlling refractory bleeding due to radiation induced proctitis. The procedure, however, is not risk free and may induce major complications such as acute colitis.