Radiation enteritis is a complication of radiation therapy to the abdomen or pelvis. Radiation therapy is sometimes used to treat certain diseases, especially cancers. In addition to killing cancer deep in the body, it damages the healthy tissue around it, such as the bowels. The damage may occur at the time of treatment or may develop over time and show up many years later.
Radiation therapy is a form of energy carefully directed at cancerous tissue. This energy is powerful enough to kill cancer cells deep in the body. All tissues overlying the cancer also are affected. For instance, radiation therapy used to treat colon cancer, ovarian cancer, or prostate cancer often severely damages healthy tissue, such as the bowels.
The bowels (intestines) are very sensitive to radiation therapy. As a result, the blood supply to the bowels can become impaired. With a poor blood supply, the affected bowel will be weakened and possibly die. Scarring of the bowel sometimes occurs, preventing the bowel from working properly. Intestinal obstructions may form as a result of the scar tissue.
Acute symptoms of radiation enteritis occur during and right after radiation therapy to any cancer of the abdomen or pelvis. These include: nausea with vomitingcramping painwatery diarrhea
These symptoms may worsen even after the radiation is completed. With treatment, these problems subside.
Chronic symptoms occur many months or years after treatment. They include: diarrheacramping painsevere weight lossloss of appetite
Sometimes an intestinal obstruction will form that will cause severe nausea and vomiting. A fistula, or abnormal opening from one part of the bowel to another organ, may also occur.
Radiation enteritis is caused by large doses of radiation treatment to the abdomen and pelvis.
It is very difficult to prevent radiation enteritis when large doses of radiation therapy are used. Effectively treating the cancer is the most important goal. Large doses of radiation may be needed to kill the cancer.
When the dose of radiation to the intestine is limited to a dose that is generally known to be a safe dose then there is a low risk for chronic radiation enteritis. This low-risk dose is usually 45 Gy given over 5 weeks as daily radiation treatments. The addition of chemotherapy may increase the risk of bowel injury from irradiation.
A person undergoing radiation therapy is observed closely for signs of radiation enteritis. The problem is identified when symptoms are reported.
Acute radiation enteritis usually resolves without lasting effects. Chronic radiation enteritis occurring many years after treatment is harder to treat. If the symptoms are not severe, they can be managed with changes in diet and other interventions. The damage may be so extensive that the person will have to undergo surgery to remove the affected bowel or to repair an opening from the bowel to another organ.
Radiation enteritis poses no risk to others.
In acute cases of radiation enteritis, diarrhea and nausea can often be controlled with medications. Failure to treat the diarrhea effectively can result in dehydration. A person may have to be admitted to the hospital in severe cases.
A diet that is low in fiber is helpful. Resting will help the person conserve energy while the bowel is healing. In chronic cases, the person may have to have surgery to remove blockages or scar tissue in the bowel. Diarrhea is likely to be a long-term problem. Medications, such as psyllium, will give the stool a firmer consistency. The person will have to focus on eating foods that do not make the diarrhea worse or cause cramping.
Bowel surgery is major surgery and requires a recovery period. Repairing a bowel opening may also entail surgery. Other therapy is designed to improve quality of life and does not generally have significant side effects.
The person will be monitored for return of symptoms or development of new problems. Follow-up visits will include discussing any new symptoms. Any new or worsening symptoms should be reported to the healthcare professional.
Careful follow-up is the most effective way to monitor for the development of radiation enteritis. There is no routine test done that can diagnose this condition. Treating the symptoms before the person becomes weakened is important. Reporting symptoms immediately to the healthcare professional will help minimize problems.
Brower, S.T, Williams, W.L., Vassilopoulou-Sellin, R.&Lustig, R. (1996)
Prevention and management of radiation toxicity in Cancer Management: A Multidisciplinary Approach. PRR: Huntington, NY. pp. 655-680.