What is flatulence and how is it affected by cancer treatment?

Flatulence, or gas, is actually a normal bodily function and, in fact, it is quite healthy. Socially, flatulence is fairly unacceptable but the fact remains...we all have "gas." Flatulence is the by-product of digestion, although when cancer treatment causes severe flatulence and/or lower abdominal pain, measures can be taken to minimize the treatment's effects. All food that enters the body is digested (broken down) into small parts (nutrients) to be absorbed into the bloodstream through the bowel wall and transported to other parts of the body.

Protein must be broken into amino acids, fats must be broken into fatty acids and carbohydrates must be broken down into glucose-like molecules. Nutrients that are not used are stored as fats or glycogen.

Sometimes, food is not completely broken down in the stomach or small intestine. There are a variety of reasons why food does not break down in the stomach or small intestine including lactose intolerance (the body lacks the enzyme lactase to break down lactose), for example. Once the food arrives in the large intestine, there are hundreds of bacteria (normal flora) that are available to help break down break down the undigested food. When this happens, a variety of gasses are released (much like the carbon dioxide released by yeast when making bread rise). These bacteria release gases like methane, hydrogen, and hydrogen sulfide. Hydrogen sulfide is the gas that causes odor.

Certain foods are more difficult to digest than other foods. Carbohydrates are the most flatulence-producing foods. Some of these include beans, bran, potatoes, fruits, vegetables (such as cabbage, broccoli, and cauliflower, onions, garlic) and even milk.

On a lighter note, flatulence, in addition to being known as gas, has also been referred to as toots, farts, honks, breaking wind and a variety of other home-concocted names.

Chemotherapy-induced abdominal pain, cramping and flatulence:

  • Chemotherapy can cause both increased (rapid) and decreased (slow) motility of the intestines. In other words, the normal wave-like action that moves stool through the bowel may be faster or slower than usual.
  • Rapid motility may cause stool to travel faster and be less formed. Rapid motility can be associated with cramping and/or diarrhea.
  • Slow motility may cause stool to travel slower, becoming harder and dryer and more difficult to pass. It may contribute to constipation and lower abdomen pain. Pain may be achy or cramp-like and may be associated with increased flatulence (gas).
  • Chemotherapy may also alter the normal bacterial flora that is present in the intestines. This can affect digestion and cause aching, cramping or flatulence (gas).
  • Steroids and other immunosuppressive medications may increase the probability of ulcers or other potentially serious abdominal complications such as perforation.
  • A history of or the development of lactose intolerance may contribute to worsening abdominal pain, cramping or flatulence (gas).
  • Cramping is a caused by a spasm (or contraction) of the bowel. It may be associated with the urge to move your bowels. It is not usually constant but comes more in "waves." It may be accompanied by either diarrhea, constipation or flatulence (gas).

Things you can do and cancer treatment-induced abdominal pain:

  • Drink plenty of fluids (2-3 quarts every 24 hours), unless you have been told to restrict your fluids.
  • Take your medication with food unless you are specifically to take it on an empty stomach.
  • Avoid aspirin or products containing aspirin and NSAIDs (non-steroidal anti-inflammatory drugs, unless your doctor specifically prescribes them.
  • Avoid narcotic pain medications if they are not needed. Do not use for abdominal pain.
  • Avoid drinking alcohol and smoking cigarettes; both can be irritating to your stomach.
  • If you are experience cramping, you may try to relax and breathe deeply to assist in relief.
  • Eat bland foods in small amounts: Similar to managing nausea and/or diarrhea.


Foods to avoid:

  • Hot, spicy foods (i.e. hot pepper, curry, Cajun spice mix).
  • Fatty, greasy or fried foods.
  • Very sweet, sugary foods.
  • Large meals.
  • Foods with strong smells (foods that are warm tend to smell stronger).
  • Eating or drinking quickly.
  • Drinking beverages with meals.
  • Lying down after a meal.

Tips for avoiding lower abdominal pain and flatulence while undergoing cancer treatments:

  • Small meals throughout the day.
  • Refrigerated or room temperature entrees.
  • Rinse mouth with lemon water after eating.
  • Suck on ice cubes, mints, or hard candies.
  • Distractions such as TV, music, or reading may be helpful while eating.

Related Side Effects

Gas has related side effects:

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