The role of nutrition
Damage to the intestinal villi from radiation therapy results in a reduction or loss of enzymes, one of the most important of these being lactase. Lactase is essential in the digestion of milk and milk products. Although there is no evidence that a lactose-restricted diet will prevent radiation enteritis, a diet that is lactose free, low fat, and low residue can be an effective modality in symptom management.[Level of evidence: I]
Foods to avoid
- Milk and milk products. Exceptions are buttermilk and yogurt, which are often tolerated because lactose is altered by the presence of Lactobacillus. Processed cheese may also be tolerated because the lactose is removed with the whey when it is separated from the cheese curd. Milkshake supplements such as Ensure are lactose free and may be used.
- Whole-bran bread and cereal.
- Nuts, seeds, and coconuts.
- Fried, greasy, or fatty foods.
- Fresh and dried fruit and some fruit juices such as prune juice.
- Raw vegetables.
- Rich pastries.
- Popcorn, potato chips, and pretzels.
- Strong spices and herbs.
- Chocolate, coffee, tea, and soft drinks with caffeine.
- Alcohol and tobacco.
Foods to encourage
- Fish, poultry, and meat that is cooked, broiled, or roasted.
- Bananas, applesauce, peeled apples, and apple and grape juices.
- White bread and toast.
- Macaroni and noodles.
- Baked, boiled, or mashed potatoes.
- Cooked vegetables that are mild, such as asparagus tips, green and waxed beans, carrots, spinach, and squash.
- Mild processed cheese, eggs, smooth peanut butter, buttermilk, and yogurt.
- Ingest food at room temperature.
- Drink 3,000 cc of fluid per day. Carbonated beverages should be allowed to lose carbonation before being ingested.
- Add nutmeg to food, which will help decrease mobility of GI tract.
- Start a low-residue diet on day 1 of radiation therapy treatment.[Level of evidence: IV]
Chronic Radiation Enteritis
Only 5% to 15% of the patients who receive abdominal or pelvic irradiation will develop chronic radiation enteritis. Signs and symptoms include colicky abdominal pain, bloody diarrhea, tenesmus, steatorrhea, weight loss, and nausea and vomiting. Less common are bowel obstruction, fistulas, bowel perforation, and massive rectal bleeding. The initial signs and symptoms occur 6 to 18 months after radiation therapy. Radiologic findings include submucosal thickening, single or multiple stenoses, adhesions, and sinus or fistula formation. Microscopic findings include villi that are fibrotic or may be lost altogether. Ulceration is common, varying from simple loss of epithelial layers to ulcers that may penetrate to different depths of the intestinal wall, even to the serosa. Lymphatic tissue is often atrophic or absent. The submucosa is severely diseased. Arterioles and small arteries show profound changes, with hyalinization of the entire wall thickness. The muscularis is often distorted or focally replaced by fibrosis.