Chemotherapy and radiation to the pelvic area are some reasons why people going through cancer treatment may experience diarrhea, which is defined as two or more loose stools per day. As with any treatment side effect, communicate with your health care team if you experience any diarrhea.

There are many things you can do to help control diarrhea. If diarrhea persists, especially large and frequent stools, you should report it to your doctor or nurse.

Making Changes to Your Diet

Many foods can nourish you without contributing to diarrhea.
Here are some suggestions for making healthy choices:



High-protein foods such as eggs (well cooked), lean meat, fish, poultry, smooth peanut butter* or beans* Fried or fatty foods (such as sausage, bacon, chicken nuggets, fried seafood or pizza)
Skim or low-fat milk, yogurt or cottage cheese (use lactose-free dairy products if you are lactose intolerant) Regular milk or cheese with more than 9 grams of fat per ounce
Cooked vegetables* such as carrots, green beans or mushrooms Raw vegetables, especially those with thick skins, seeds or stringy fibers such as broccoli
Fresh fruits without the skin or canned fruit such as applesauce (except prunes) Dried fruits
Desserts low in fat and lactose, such as sorbets, fruit ices or graham crackers High-fat ice creams or any candies, gum, or breath mints containing sorbitol, mannitol or xylitol

Note: Foods marked with an asterisk (*) are high in soluble fiber, which forms stools but also can increase the amount of stool. Choose them when you can manage more stools. For more information on nutrition, read our fact sheet titled “The Importance of Nutrition During Treatment.”

Stay Hydrated

Drinking plenty of water is important if you experience diarrhea. To avoid dehydration, try avoiding caffeinated beverages like coffee. You may also want to consider drinks such as Gatorade or Pedialyte. These drinks provide electrolytes—the body’s salts—which must stay in balance for cells to work properly.

Taking Medicine for Diarrhea

Talk to your doctor about what treatment option is best for you when experiencing diarrhea. The most recommended over-the-counter medicine for diarrhea is loperamide (Imodium and others). Over-the-counter medicines can be quite powerful. In general, if the diarrhea is bad enough for you to need any type of medicine, including an over-the-counter one, you should consult your health care team.

Side effects vary from person to person. Your doctor may need to prescribe a stronger medication such as diphenoxylate and atropine. Like all medicines, these products can interact with other drugs you may be taking, such as opiate pain relievers. Be sure to report to your health care team any reactions you experience.

For severe diarrhea that does not respond to these oral medications, your doctor may consider giving you injections of octreotide (Sandostatin and others). Although this drug has not been approved specifically for diarrhea caused by chemotherapy or radiation treatments, your doctor may choose to prescribe it “off label.”