Improvement of Chronic Diarrhea Associated With Radiation Enteritis With Cholestyramine Therapy

Abstract

Introduction: Radiation enteritis is a well-described complication of pelvic or abdominal radiation therapy. Its presentation can be acute, occurring within hours to weeks of therapy, or chronic, appearing within years to decades. Symptoms vary, and can include anorexia, nausea and vomiting, small bowel obstruction, and diarrhea. The most common mechanism to explain diarrhea in chronic radiation enteritis is bile acid malabsorption. Excess bile salts in the colon stimulate water secretion, leading to increased motility and diarrhea. We present a patient who received pelvic radiation for a testicular seminoma while in his thirties, developed symptoms of radiation enteritis in his fifties, and was successfully treated with cholestyramine at age 74. Cholestyramine irreversibly binds bile salts, thus acting as a surrogate ileum and preventing concomitant electrolyte and water secretion into the colon.