Foods to Eat for Diarrhea During Cancer Treatment

Diarrhea is one of the many potential side effects of cancer treatment. Radiation therapy to the abdominal area (mid-section of the body) can cause diarrhea, as can certain chemotherapy medications. If you struggle with diarrhea, there are several things you can do to address the problem and help your body heal.

Broth in a mug on a plate with a spoon and garnish
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Use Medications Your Healthcare Provider Has Prescribed

The most important thing you can do to control diarrhea during cancer treatment is to take medications as prescribed. As with many treatment side effects, prevention is more effective than cure. Once diarrhea is very severe, it can be more challenging to bring under control.

Severe diarrhea causes dehydration and loss of important electrolytes (minerals), including sodium and potassium. This can be a life-threatening situation, so do not ignore diarrhea. If your medical team prescribes medication to prevent diarrhea, do not wait until you have diarrhea to take it. For some cancer treatments, taking anti-diarrheal medications before the problem occurs is part of the plan.

Foods to Help You Manage Diarrhea

In addition to medical management, the following food tips and tricks may help you manage diarrhea. As with any nutrition advice, these nutrition tips may not be appropriate for everyone, such as people with an intestinal blockage. If you have questions about whether these tips are right for you, talk to your healthcare team.

  • Eat more high-soluble fiber foods including plain oatmeal, white rice, ripe bananas, applesauce, white toast, canned fruit without the skins, such as peaches and pears, white pasta noodles, cream of rice cereal and plain unsweetened graham crackers.
  • Drink 8 cups of non-caffeinated fluid each day to prevent dehydration. Try water; coconut water; decaf, chamomile and ginger teas; ginger ale; rice milk; and diluted fruit juices and nectars, such as peach, pear, mango or papaya nectar (avoid grape and prune juices).
  • Sip plain broth or bouillon, flat soda, and water.
  • Try clove tea, which can help replace fluids and may lessen the severity of diarrhea.
  • Drink most of your liquids between meals.
  • Snack on plain, salty foods, such as crackers and pretzels, to replace lost sodium.
  • Eat a little plain yogurt daily. Yogurt contains healthy bacteria (probiotics) that help your body digest food better.

How to Eat Is as Important as What You Eat

  • Eat 5 to 6 small snacks or mini-meals daily instead of 2 to 3 bigger meals.
  • Have only a few bites of any food at one time. Too much food will overload your body and worsen diarrhea.
  • Sip liquids very slowly but continuously throughout the day. For example, take a small sip of liquid every 15 minutes.
  • Drink liquid at room temperature. Avoid very hot and very cold drinks.
  • For each episode of diarrhea, drink an additional cup of fluid. Remember to sip slowly to avoid overloading your digestive tract.

Things to Avoid With Diarrhea

  • High insoluble-fiber foods, including fresh fruit with the skin or peel (flesh of fruits are OK), ​raw vegetables (well-cooked vegetables are OK), whole grain bread and cereals, beans, peas, and popcorn. Insoluble fiber worsens diarrhea.
  • High-fat and greasy foods, including pizza, fried meats, bacon, french fries, mayonnaise, cheese, rich desserts, cakes, cupcakes, donuts, cookies, pastries, potato chips, gravy, and butter.
  • Cow's milk, because some treatments cause temporary lactose intolerance. Lactose intolerance causes diarrhea. Typically, lactose intolerance that develops during cancer treatment this will improve when you have finished treatment (rice, soy, and other kinds of milk are usually OK).
  • Caffeinated drinks such as coffee, soda, or large amounts of black or green tea. Caffeine can worsen diarrhea.
  • Strong spices and herbs, especially "spicy hot" flavorings, such as cayenne pepper, hot sauce, salsa, and Tabasco sauce.
  • Very hot and very cold foods. Temperature extremes can worsen diarrhea.
  • Sugar-free food, gum, and candy, which contain sugar alcohols such as sorbitol. Sugar alcohols can worsen diarrhea.
  • Tobacco (cigarettes, pipe, or chewing tobacco) and alcohol. These items worsen diarrhea.

When Should I Call My Healthcare Provider About Diarrhea?

Call your healthcare provider if you experience any of these symptoms:

  • You experience more than 5 episodes of diarrhea or loose stools per day with no improvement after 2 days.
  • You see blood in your stool or in the toilet after a bowel movement.
  • You lose more than 4 pounds due to diarrhea.
  • Your diarrhea is accompanied by a fever.
  • Your abdomen ("stomach" or mid-section) becomes puffy, swollen, or sore.
  • You have used anti-diarrheal medications (per your healthcare provider's instructions) and you do not have improvement in your diarrhea within 36 hours.
  • Your diarrhea is accompanied by persistent cramps, nausea, or vomiting.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  • American Dietetic Association, Oncology Nutrition Dietetic Practice Group. The Clinical Guide to Oncology Nutrition, 2nd Edition, 2008. Eds. Elliott L, Molseed LL, McCallum PD, Grant B.
  • USDA National Nutrient Database for Standard Reference. Accessed August 17, 2009.

By Suzanne Dixon, MPH, RD
Suzanne Dixon, MPH, MS, RDN, is an award-winning registered dietitian and epidemiologist, as well as an expert in cancer prevention and management.