Going through cancer treatments can cause a variety of side effects. Thankfully many can be supported and minimized with some nutrition strategies. Diarrhea in particular is a common side effect caused from some chemotherapies and some cancers themselves, such as hormone-producing (neuroendocrine) tumors, including carcinoid syndrome and Zollinger-Ellison syndrome, colon cancers, lymphomas, pancreatic cancers, and medullary carcinomas of the thyroid. Receiving radiation to the abdomen, pelvis, and lower back can also result in diarrhea. The severity depends on your radiation dose and duration—it can persist for weeks or months. It is also possible for diarrhea to begin months or even years after treatment or surgery. If certain parts of your intestine are removed to eliminate cancer, then this might affect your bodies ability to absorb nutrients or fat, resulting in diarrhea. Other causes can be infections, food sensitivities, anxiety, stress, graft versus host disease, or bone marrow stem cell transplants.

With diarrhea, food can pass through the bowel before your body has a chance to absorb nutrients, vitamins, minerals, and water. This can result in dehydration, weight loss, malnutrition, poor appetite, weakness, or low electrolytes (sodium, potassium, magnesium, calcium, chloride, and phosphate). It is important to be proactive when diarrhea starts to prevent these potential side effects from occurring. Below are some tips that have helped many of my patients and may be worth trying.

Focus on…

  • Easy-to-digest and bland foods as they are usually better tolerated. Try white toast, noodles, oatmeal, cream of wheat, chicken, turkey, fish, lean beef, yogurt, cottage cheese, peanut butter (smooth only), potatoes, eggs, and white rice.
  • Foods higher in salt and potassium to replace what is lost from loose stools. Good foods to try are soups, saltines, pretzels, bananas, peaches, and sports drinks (low in sugar).
  • Small frequent meals. Your body may have an easier time with digesting less food in one sitting.
  • Drink plenty of fluids. Have 8 ounces of fluid after a loose stool to help prevent dehydration. Drink mostly mild, clear, non-carbonated liquids at room temperature.
  • Once diarrhea has stopped, slowly start eating foods with fiber.
  • Focus more on soluble fibers that help with binding like applesauce, bananas, canned peaches, pears, oats, oatmeal, and sweet potatoes.
  • Canned fruits or veggies, well cooked veggies, and peeled fruits.
  • Lie down about 30 minutes after a meal.


  • Lactose containing foods such as milk as these can make diarrhea worse. Small amounts (1-1.5 cups per day) may be okay in some. Lactose intolerance can occur due to radiation to the stomach or digestive track. Yogurt and buttermilk are ok for most and you can try soy or almond milk too.
  • High fat foods such as fried and greasy foods.
  • Limit foods and beverages that contain sugar, fructose, and high-fructose corn syrup.
  • High-insoluble-fiber foods such as raw veggies, seeds, nuts, whole grains, beans, peas, dried fruits, and raw fruits except bananas. Try to choose grains with fewer than 2 grams of fiber per serving. Avoid skin, seeds, and stringy fibers of unpeeled fruits and veggies.
  • Very hot or cold food or beverages.
  • Caffeine
  • Spicy foods
  • Alcohol
  • Tobacco
  • Do not chew sugar free gum or candies and desserts made with sugar alcohol like sorbitol, mannitol, or xylitol. This may make diarrhea worse.
  • Canned fruit in heavy syrup (look for light syrup or soaked in water instead).
  • If you are taking a vitamin C supplement, you may wish to stop temporarily until the diarrhea resolves.

If you have sudden, short-term diarrhea, try having only clear liquids for the next 12-24 hours. Let your bowels rest and replace the important fluids lost. If you tolerate clear liquids well, then you can try other liquids or soft, bland foods to see how you tolerate these. Most nutrition supplement drinks like Ensure and Boost are lactose-free and may be a good option to help meet your nutrition needs if you’re not able to eat well. Call your doctor if you have 6 or more loose stools per day for more than two days, weight loss, diarrhea after several days of constipation, a swollen abdomen, fever, or any other reason your medical care provider may have recommended. Your medical team may need other medical interventions to help with lessening or preventing your diarrhea if these suggestions do not work. Remember, it is important to keep your medical care team updated to prevent treatment delays, hospitalizations, dehydration, and to help with improving your quality of life.

This post originally appeared on Survivors’ Table. It is republished with permission.