Problems in the Bowel (Radiation Enteritis) With their rapidly dividing cells , the membranes lining the large and small bowel and the rectum are quite sensitive to even low doses of radiation. So any radiation delivered to the upper abdomen or pelvis can cause an irritation of the bowel known as radiation enteritis.
Only 5 to 15 percent of people treated with radiation to the abdomen will develop chronic problems, and the severity of the symptoms will depend on several factors—how much of the abdomen or pelvis is irradiated, the daily dose, the total dosage required and the possible use of chemotherapy at the same time. People with a history of abdominal surgery, pelvic inflammatory disease, atherosclerosis, diabetes or hypertension are also more likely to suffer radiation injury.
Symptoms If you are getting radiation to the upper abdomen, you may experience bouts of nausea and vomiting. Pelvic irradiation is more likely to cause irritation in the rectum, frequent bowel movements or watery diarrhea. These disturbances to the intestinal mucosa may change the way your gastrointestinal tract absorbs nutrients from the food you eat. It may become much more difficult to absorb fat, bile salts and vitamin B12, for example.
Your doctor will evaluate the extent of the enteritis by assessing how often you have diarrhea, the character of the stools, whether you have any rectal bleeding and whether your abdomen is enlarged (distended). He or she will also watch for possible dehydration or an electrolyte mineral imbalance in your blood resulting from diarrhea and/or malabsorption.
