Diarrhea, like constipation, can be caused by tumors located in the gastrointestinal tract or by methods of cancer treatment. About 75 percent of persons being treated with chemotherapy or radiation therapy to the abdominal region experience this symptom. The degree and duration depend on the dose and the duration of therapy. Diarrhea usually continues for two to three weeks after treatment.
Anxiety and increased stress tend to increase the secretion of gastric juices and gastrointestinal motility, contributing to diarrhea. Other causes include lactose intolerance (the inability to digest regular milk and milk products), fecal impaction, and dietary supplements that have a high osmolarity, meaning they tend to draw water into the intestines.
To prevent or minimize diarrhea, a low-residue diet that is high in calories and protein but low in fat and fiber is recommended. Foods to emphasize include:
- Cottage cheese and low-fat cheeses (if the patient can tolerate milk products).
- Eggs (not fried).
- Boiled low-fat milk, natural yogurt, buttermilk.
- Broth, bouillon, consomme.
- Fish, poultry, and ground beef that is baked, broiled, or roasted until tender.
- Rice pudding, custard, and tapioca (made with low-fat milk), and gelatin.
- Cooked cereals such as cream of wheat or rice.
- Bananas, applesauce, peeled apples (apples contain pectin, a natural antidiarrheal agent), apple juice, grape juice.
- White bread, toast, crackers made with refined flour.
- Macaroni, noodles, white rice.
- Baked, boiled, or mashed potatoes.
- Cooked, mild vegetables such as asparagus tips, beets, green and wax beans, carrots, peas, spinach, squash; also cream soups from these vegetables.
- Nutmeg, which may decrease the motility of the gastrointestinal tract and should be added to foods wherever appropriate.
- Foods and beverages that should be avoided are any that might irritate or stimulate the gastrointestinal tract. These include:
- Whole-grain bread and cereal such as bran and granola.
- Nuts, seeds, coconut.
- Fried and greasy or fatty foods such as pork.
- Fresh and dried fruits, fruit juices except those mentioned above.
- Raw vegetables.
- Rich pastries.
- Popcorn, potato chips, pretzels, nuts.
- Strong spices and herbs such as chili powder, licorice, pepper, curry, garlic, horseradish.
- Olives, pickles, and relishes.
- Flatus-forming foods such as broccoli, onions, and cabbage.
- Foods and beverages containing caffeine, such as chocolate, coffee, tea, caffeine-containing soft drinks.
- Alcoholic beverages, including liquor, beer, and wine.
- Tobacco products.
If diarrhea is present, the patient should report it to the physician or nurse and keep a record of the number, amount, and character of the bowel movements. Kaopectate or Pepto-Bismol may be effective for mild diarrhea, but for diarrhea lasting longer than a couple of days the physician may want to prescribe something stronger, such as Lomotil or paregoric.
If weakness or fatigue accompanies the diarrhea, potassium levels may be depleted and the patient should include high-potassium foods such as baked potatoes, bananas, green beans, halibut, and asparagus tips in the diet. Potassium supplements may be necessary if diarrhea persists, although these supplements often cause gastrointestinal discomfort.
To help prevent dehydration, at least eight to ten glasses of liquid should be consumed daily. Especially good are the following, which help restore sodium, potassium, and other important ions to the body: bouillon, fruit ade, apple juice, grape juice, Gatorade, weak tepid tea, and gelatin. Caffeine-free carbonated beverages that are allowed to go flat before drinking are also acceptable (carbonation may aggravate diarrhea). If the diarrhea is severe, eliminate solid foods and limit the diet to these liquids, then gradually add low-residue foods to the daily diet.
People experiencing diarrhea should eat small, frequent meals and avoid extremely hot or cold foods. Since extremes in temperature may aggravate diarrhea, foods should be served warm or at room temperature.
If the diarrhea is caused by lactose intolerance, the person should avoid all regular milk and milk products used alone or in cooking and baking, as well as cheese, ice cream, and sour cream. Cocoa and chocolate should also be avoided, since these foods contain lactose.
The following dairy products are usually tolerated:
- Buttermilk and yogurt. Lactose is altered by the lactobacillus contained in these foods.
- Processed cheese.
- Lactose-free dairy substitutes (brands include Non-Dairy Creamer, Dairy Rich, Cool Whip and Party Whip).
- Milk with Lact-aid, a tablet containing lactase, which digests the milk within twenty-four hours, rendering it lactose-free.
- Lactose-free nutritional supplements such as Ensure or Citrotein.
- If the anal area becomes irritated by frequent bowel movements, the person can:
- Cleanse the anal area after each bowel movement with warm water and a mild soap such as Dove or Ivory, rinse well, and pat dry with a soft towel.
- Apply a perianal cream such as Desitin or Proctodon.
- Apply a local anesthetic in ointment or spray form. Corticosteroid sprays or creams may be prescribed by the physician to reduce inflammation.
- Take frequent sitz baths or sit in a tub of warm water.
- Wear loose-fitting clothing and allow the area to be exposed to the air.
- Wear a sanitary napkin or a product such as Assure if incontinent of ‘ liquid stool, to avoid embarrassment and the need for frequent changes of clothing.