Managing Diarrhea During Chemotherapy

Managing diarrhea during chemotherapy can improve a cancer patient's lifestyle. Diarrhea, a common side effect of chemotherapy, can cause skin irritation, stomach pain and cramping, and loss of appetite. Chemotherapy-induced diarrhea is caused by chemotherapy drugs affecting the lining of the intestine. Diarrhea during cancer treatment can also occur because of stress, anxiety, malnutrition, or surgery to the bowel or colon.

Person pouring medication pills into hand
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What Is Cancer?

Cancer can start any place in the body. It starts when cells grow out of control and crowd out normal cells. This makes it hard for the body to work the way it should and causes problems in the part of the body where the cancer started.

Cancer cells can also spread to other parts of the body. For instance, cancer cells in the lung can travel to the bones and grow there. When cancer cells spread, it’s called metastasis. When lung cancer spreads to the bones, it’s still called lung cancer. To doctors, the cancer cells in the bones look just like the ones from the lung. It’s not called bone cancer unless it started in the bones.

Some cancers grow and spread fast. Others grow more slowly. They also respond to treatment in different ways. Some types of cancer are best treated with surgery; others respond better to drugs called chemotherapy. Often two or more treatments are used to get the best results.

When someone has cancer, the doctor will want to find out what kind of cancer it is. People with cancer need treatment that works for their type of cancer.

What Is Chemotherapy?

Chemotherapy is the use of any drug to treat any disease. But to most people, the word chemotherapy means drugs used for cancer treatment. It’s often shortened to “chemo.”

Surgery and radiation therapy remove, kill, or damage cancer cells in a certain area, but chemo can work throughout the whole body. This means chemo can kill cancer cells that have spread (metastasized) to parts of the body far away from the original (primary) tumor.

Tips for Avoiding and Managing Diarrhea

  • Drink beverages at room temperature. Extremely hot or cold beverages may upset the stomach.
  • Avoid greasy, fatty foods. Fried, fatty or greasy foods are very heavy on the stomach and can cause diarrhea.
  • Drink 8-10 glasses of clear liquids. Clear liquids don't have to be boring. Jell-O, water, broths, and sports drinks are all excellent examples of clear liquids.
  • Avoid foods that cause gas. Foods and drinks like carbonated beverages, beans, and cabbage. If you must have carbonated drinks, allow the "fizz" to go down before drinking.
  • Avoid dairy. If milk and other dairy products worsen or cause diarrhea, avoid them.
  • Eat foods low in fiber. You don't want to stimulate the bowel. The goal is to still be able to eat small amounts without overexerting the bowel. Try eating bananas, rice, white meat chicken and white bread in small amounts.


When being treated for cancer, it is essential to ask your physician before using any medications, including over-the-counter (OTC). There are several OTC medications for diarrhea, such as Pepto Bismol, Immodium, and Maalox.

Herbal teas are available, but you must run by any herbal supplements or teas with your doctor before use.

The most common prescription drug used to combat chemotherapy-induced diarrhea is Diphenoxylate or Lomotil by its trade name.

When to Call the Doctor

Call your doctor if you experience black, bloody, or tar-like stools, moderate to severe bloating and cramping, dizziness and a fever of 100.5 F or more.

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