Diarrhea is the passing of loose or watery stools three or more times a day. Diarrhea may cause cramps in the abdomen and pain or discomfort in the rectum. When mild, diarrhea is an inconvenience, but left untreated it can lead to serious problems, such as dehydration, loss of important nutrients, weight loss, and fatigue.

Who is most likely affected?

Diarrhea is most likely to affect individuals who had surgery on the intestines, who are being treated with radiation to the abdominal area, or who are receiving certain chemotherapy drugs.

Diarrhea also can occur in people taking targeted therapy drugs, although it is usually mild. In addition, people who receive a bone marrow transplant are often affected by diarrhea.

If patients are taking antibiotics as part of their cancer treatment, they might develop an antibiotic-associated diarrhea which could be serious and even life threatening. Virtually any antibiotic can cause antibiotic-associated diarrhea, but the most common causes are ampicillin, clindamycin, and cephalosporins.

Why does this occur?

Diarrhea can be caused by the inability of the intestines to absorb water, overaction of the muscle layer of the intestine, or damage to the rapidly dividing cells that line the intestines so they cannot perform their function of absorbing liquids.

When does this occur?

Cancer treatment-related diarrhea is a short-term side effect. It typically occurs within the first few days or week after treatment and usually resolves within a few weeks after the end of treatment. Diarrhea caused by bone marrow transplantation may last for a week to a few months after the end of treatment.

How can this be managed?

Changes in diet can help prevent or minimize diarrhea. Once diarrhea occurs, following a diet of only clear liquids may help the lining of your intestines heal. Clear liquids include water, apple or cranberry juice, ginger ale, clear broth, popsicles, and Jell-O. As diarrhea begins to improve, you can slowly add solid foods to your diet, starting with low-fiber foods. You should also eat foods that are high in potassium, as this important mineral is often lost during diarrhea. Some foods can make diarrhea worse, such as dairy products (milk, cheese, and sour cream); spicy, greasy, or fried foods; raw fruits or vegetables; or foods that are high in fiber (whole-wheat breads, granola, and bran cereals).

Medications are also available to control diarrhea. Some of these medications are available over-the-counter. Fiber supplements may also be useful. You should not take any over-the-counter antidiarrheal medications without talking to your doctor first. Your doctor may give you instructions for taking these drugs that differ from those on the drug label. If diarrhea is severe, your doctor can prescribe other medications.Your doctor may also stop treatment with targeted therapy temporarily and restart it when diarrhea is controlled.
Severe diarrhea may cause discomfort in the rectal area. To help soothe this area, clean the external rectal area with warm water and soap after bowel movements, soak in a warm bath, or use a water-repellent cream.

Ways to Help Prevent Diarrhea

Drink 6 to 8 glasses of fluid per day	Examples: water, sports drinks (Gatorade), broth
Avoid beverages with alcohol or caffeine	Examples: beer, wine, cola, coffee, black tea
Eat bland, low-fiber foods	Examples: boiled white rice, cheese, boiled chicken, mashed potatoes
Eat foods high in protein, calories, and potassium that are easy to digest	Examples: cottage cheese, eggs, baked potatoes, cooked cereals, bananas, macaroni and pasta, white toast, applesauce, apricots, crackers, pretzels, smooth peanut butter
Eat more frequently but in smaller amounts	Example: Eat 5 to 6 small meals rather than 3 large meals
Add nutmeg to foods	This spice slows down the movement of material through the intestines
Avoid foods that are very high in fat	Examples: fried or greasy food, cream sauces
Avoid fluids and food that can irritate the digestive tract	Examples: caffeine (cola, coffee, tea), alcohol, milk or milk products, chocolate, dried fruits, beans, popcorn, spicy food
Avoid very hot and cold beverages

When should I talk to my doctor?

Talking about diarrhea may seem embarrassing, but it is important to control diarrhea to avoid complications. Talk to your doctor if diarrhea is persistent and resistant to over-the-counter medications, especially if you have recently been taking antibiotics. Also, call your doctor if you have symptoms of severe dehydration, such as dizziness or fainting.

Call your doctor immediately if you:

Have 6 or more loose bowel movements per day for more than 2 days in a row
Notice blood in the stool, around the anal area, on the toilet paper, or in the toilet bowl
Cannot urinate for at least 12 hours
Have signs of a fever
Lose 5 pounds or more after the diarrhea starts
Have a swollen and/or painful abdomen
Feel dizzy or lightheaded when moving to a standing position