Flatulence (Passing Gas)

Author: Marisa Healy, BSN, RN
Last Reviewed: April 04, 2023

What is it?

Flatulence is also called passing gas or passing wind. Everyone passes gas throughout the day. When you are getting cancer treatment, you may have an increase in how much or how often you pass gas. There are a few reasons this may happen:

  • Constipation or diarrhea may cause your body to make more gas. Some cancers, stress, medications, and radiation therapy can cause gas, constipation, and diarrhea.
  • Chemotherapy medicines can change how you digest food, either speeding it up or slowing it down. Even when these changes do not cause constipation or diarrhea, they may cause more gas to be made. Chemotherapy may also change the bacteria in your digestive system, making more gas.
  • Other medications that can cause more gas are antacids, antibiotics, nutritional supplements, and non-steroidal anti-inflammatory pain relievers (NSAIDS).

Passing gas is normal, but too much gas can be embarrassing or uncomfortable. It can cause cramping, pain, or bloating. Often, once treatment ends your body will make less gas.

How can I manage gas?

Each person’s body can react differently to foods. You may want to start a food diary to write down what you eat each day, how your body reacts to those foods, and how you are feeling. You may be able to figure out which foods cause you more gas than others.

Some ways you can decrease gas are by:

  • Exercising, which can help constipation and help with digestion, especially after eating a large meal. Examples of exercise are walking, swimming, or gardening.
  • Eating smaller meals more often and eating at the same time each day. Spicy and fatty foods can increase gas so try to avoid them.
  • Eating slowly, not drinking while eating, and not talking while eating. This can help decrease how much air you swallow while eating.
  • Not using a straw when drinking and not drinking caffeinated (coffee and tea) or carbonated drinks (soda, beer, seltzer water). You should also avoid chewing gum since you swallow more air when chewing gum.
  • Limiting use of artificial sweeteners (erythritol, mannitol, sorbitol, and xylitol). These sweeteners are found in some gums and sugar-free or low sugar foods and may cause more gas.
  • Limiting alcohol and smoking as these can affect digestion.
  • Foods that make a lot of gas are:
    • Onions, celery, carrots, broccoli, brussels sprouts, cucumbers, cabbage, cauliflower, leeks, radishes, parsnips, green salad, and garlic.
    • Bananas, apricots, prunes, and dried fruit.
    • Bagels, wheat germ, pretzels, bran cereal, and brown rice.
    • Peas and beans.
    • Sugar alcohols, carbonated drinks, caffeinated drinks, and chewing gum.
    • Dairy products such as milk, yogurt, and cheese.
  • Foods that make some gas are potatoes, eggplant, citrus fruits, apples, pastries, and breads.
    • Meat, poultry, fish, and nuts.
    • Lettuce, peppers, avocado, tomato, asparagus, zucchini, okra, and olives.
    • Cantaloupe, grapes, and berries.
    • White rice, chips, popcorn, graham crackers, fruit ice, and gelatin.
    • Eggs.

When should I call my care team?

There are over the counter medications, such as simethicone, that can be used to help with your gas. Ask your provider which one is right for you. If intestinal gas is causing you cramping, bloating or pain, or you are having other symptoms, such as new onset of constipation, "pencil-shaped" stools or blood in stool, call your care provider.


Breastcancer.org. 2019. Gas (Flatulence).

Fink RN, Lembo AJ. Intestinal Gas. Current Treatment Options in Gastroenterology. 2001:4.333-337.

Muls, A. C., Watson, L., Shaw, C., & Andreyev, H. J. N. (2013). Managing gastrointestinal symptoms after cancer treatment: a practical approach for gastroenterologists. Frontline gastroenterology, 4(1), 57–68. https://doi.org/10.1136/flgastro-2012-100218


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