Abramson Cancer Center of the University of Pennsylvania
Last Modified: March 20, 2009

Diarrhea is the passage of loose or watery stools three or more times a day that may or may not cause pain or discomfort in the abdomen and/or rectum.  Because diarrhea can cause many problems, including dehydration, loss of important nutrients, weight loss, and fatigue, it should never be ignored or left untreated.

What Causes Diarrhea?

  • Diseases of the bowel
  • Some chemotherapy agents, as well as radiation therapy and surgery involving the bowel
  • Certain medications
  • Bowel infections
  • Anxiety
  • Certain foods and nutritional supplement drinks
  • Severe constipation may result in leakage of stool

What Can I Do to Prevent Diarrhea?

  • Eat bland, low-fiber foods such as boiled white rice, cheese, boiled chicken, and mashed potatoes.
  • Choose foods high in protein, calories and potassium that are easy to digest such as cottage cheese, eggs, baked potatoes, cooked cereals, bananas, macaroni and pasta, white toast, applesauce, crackers, pretzels and smooth peanut butter. 
  • Avoid foods that are very high in fat.
  • Eat small amounts of food 5-6 times throughout the day, instead of three large meals.
  • Add nutmeg to foods in order to slow down the movement of material through the intestines.
  • Drink 6-8 glasses of fluid per day. Besides water, consider fluids that replace minerals lost in diarrhea such as: sport drinks (Gatorade®) or soup broth.
  • Clear liquids may be easier to tolerate.  Try fruit clear juices like apple or cranberry, ginger ale and jello.
  • Avoid caffeine (cola, coffee, tea), alcohol, milk or milk products, chocolate, dried fruits, beans or popcorn as well as fatty, fried, greasy or spicy foods.
  • Avoid very hot and cold beverages.

Care of the rectal area:

  • Clean the external rectal area well after each bowel movement. Use warm water and soap, and pat dry with a soft towel. This will help to prevent anal burning.
  • Inspect the rectal area daily for red, scaly or broken skin. Report this to your doctor or nurse.
  • Soak in a warm bath or use a sitz bath, which delivers a continuous, gentle flow of warm water over the rectal area while sitting on the toilet. Sitz baths can be purchased at your local drug store.
  • Water-repellent creams, available over-the-counter at your drug store, such as A & D ointment, are very effective. Ask your doctor about a numbing ointment if the area becomes very sore.

Can I take over-the-counter medications?

You should not take any over-the-counter medications while receiving chemotherapy without discussing them with your doctor or nurse first.  This includes all over-the-counter anti-diarrheal medications, such as Kaopectate®, Immodium AD® and Pepto-Bismol®. This is because diarrhea can be caused by an infection or due to a medication you are receiving.  Your healthcare team will want to determine this before you take any medication to stop the diarrhea and may give you instructions for taking the medications that are different from those on the package.

When Should I Call My Doctor?

Diarrhea should not be ignored, since it can result in loss of fluid and nutrition and can be uncomfortable. Call your doctor immediately if you have any one or more of the following:

  • 6 or more loose bowel movements per day for more than 2 days in a row
  • Blood in or around the anal area, in the stool, on the toilet paper or in the toilet bowl
  • No urine for 24 hours
  • Inability to drink liquids for more than 24 hours
  • Fever
  • Weight loss of 5 pounds or more since the diarrhea started
  • Swollen and/or painful abdomen