Short-chain fatty acids in the treatment of radiation proctitis: a randomized, double-blind, placebo-controlled, cross-over pilot trial

PURPOSE: Treatment of chronic radiation proctitis remains unsatisfactory. Short-chain fatty acids are the preferred energy source for the colonic epithelium. We aimed to determine for the first time whether topical butyric acid enemas relieve symptoms and improve the macroscopic and microscopic findings in chronic radiation proctitis. METHODS: A randomized, double-blind, placebo-controlled, cross-over pilot trial compared patients given two weeks of butyric acid enemas (40 mmol) twice per day with those given placebo, with a one-week washout period; 15 patients were randomized and 12 completed both arms of the trial. A total symptom score combined six symptom items per week (rectal pain, episodes of rectal bleeding, amount of blood passed, days with diarrhea, number of stools, and urgency). Symptom, endoscopic, and histologic scores were obtained at the beginning of the study and again at the last week of each treatment arm. RESULTS: Total symptom score at baseline (median, 5.5) improved for those patients receiving active treatment (median, 3.5), but compared with placebo (median, 4.5), the change was not significant. Endoscopic appearances were largely unaltered by active treatment. Histology was abnormal in 82 percent of patients receiving placebo compared with 55 percent of those given butyric acid enemas (P = not significant). CONCLUSION: Butyric acid enemas do not appear to be superior to placebo in the treatment of chronic radiation proctitis.