Radiation is used in the treatment of cancer and comes with risks. Radiation enteritis is one of these risks. This condition is caused by the inflammation of your small and/or large intestine from radiation treatments in your stomach, sexual organs, or rectum. Radiation enteritis can cause the loss of both intestinal cells and tissue.There are two types of radiation enteritis: acute and chronic. Acute enteritis develops while you are getting radiation treatments. The condition will last until about eight weeks after your last radiation treatment. Chronic enteritis can cause symptoms that last for months to years after you complete your radiation treatment.