Radiation Enteritis

Definition:

Enteritis occurs when the lining of the small intestine swells and becomes inflamed. When the abdomen is radiated, the normal intestine in the radiation field can be damaged. Side effects including nausea, vomiting, and diarrhea often occur during or immediately after radiation therapy. Damage that persists and causes long-standing inflammation in the intestine is called radiation enteritis and results in long-term diarrhea.  This may not become clinically noticeable until as late as 20 years after completion of radiation therapy.

Alternative Names:

Radiation enteropathy; Radiation-induced small bowel injury

Causes, incidence, and risk factors:

Exposure of the abdomen to radiation can cause radiation enteritis. Anyone whose cancer requires radiation therapy to the abdomen (such as women with ovarian,  cervical or uterine cancer or anyone with rectal cancer) is at risk. When the normal intestine in the radiation field becomes inflamed (enteritis), a patient can develop nausea, vomiting and diarrhea. These symptoms often occur during or immediately after radiation therapy.

If the damage lasts only a short time, it is called acute radiation enteritis, but if damage persists and causes long-standing inflammation in the intestine, it is called chronic radiation enteritis and results in long-term diarrhea.

Symptoms:

Diarrhea – this may often relate to bacterial overgrowth or malabsorption from damaged intestinal lining
Nausea – this may be caused by a bowel obstruction related to scar tissue from the radiation
Vomiting
Weight loss
Anorexia

Signs and tests:
Usually, diagnosis is made by physical exam and history. Occasionally, your doctor may order a small bowel x-ray to look at an outline of the lining of intestine directly.

Treatment:

Unfortunately, there often are no good treatments for chronic Radiation Enteritis. Symptomatic control is the best approach. This includes eating small frequent meals and taking anti-diarrheal or anti-spasmodic agents, treating bacterial overgrowth if present, and TPN.