Woman with flatulence

Flatulence can be very embarrassing if we find ourselves in the wrong setting when it happens.

Flatulence is also known as intestinal gas or farting.

Excessive intestinal gas is a common compliant of patients visiting family physicians and an even more common complaint heard by gastroenterologists.

Symptoms of excessive intestinal gas include belching (burping), bloating, abdominal pain and farting.

99% of bowel gas is comprised of five gases:

  • nitrogen
  • oxygen
  • carbon dioxide
  • hydrogen
  • methane

There are 3 major ways that gas enters the intestines

  • air that is swallowed (food and liquids have gases within them or that are released when chemically broken down)
  • gas that is produced in the guts
  • diffusion of gases from the blood into the bowels

One example of gas being produced in the digestive tract is when stomach acid (and other sources of acid) reacts with, and is neutralized by, bicarbonate to produce carbon dioxide.

Another source of gas production in the guts is the bacterial production of gas (volatile metabolites).

Skatole, also known as 3-methylindole, is a volatile molecule produced by bacteria in the gut and is the primary, foul odor molecule of feces and farts.  Hydrogen sulfide, the rotten egg smell gas, is another noxious gas that can be produced by bacteria in the bowels.

A significant source of gas is carbohydrates that are not completely absorbed by the small intestine and that are fermentable.  Bacteria found in the large intestine cause the fermentation of these carbohydrates leading to increased gas.

Beans contain a large quantity of carbohydrates known as oligosaccharides.  Oligosaccharides are a great example of carbohydrates that are not absorbed by the small intestine and produce a lot of gas in the large intestine.

Not everyone has the bacterial flora in their intestines that leads to the production of methane gas.  In fact, having methane-producing bacteria in your guts seems to be an environmentally acquired, family trait.

Foods that can cause flatulence include:

  • dairy products
  • fruit
  • dried fruits
  • foods with high content of insoluble fiber such as seeds
  • legumes such as chickpeas and soybeans
  • vegetables

The treatments for flatulence include supplementation with digestive enzymes, probiotics, rifaxim, gas-reducing agents such as simethicone and bismuth subsalicylate (Pepto-Bismol) to reduce odor.

To learn more about other embarrassing health issues visit our Conditions page.