What Is Flatulence?
Flatulence — commonly known as farting — is the release of intestinal gas through the rectum. It is a completely normal part of human digestion, occurring on average 14 to 23 times per day in healthy adults.
How Gas Gets Into the Gut
Intestinal gas has two main origins: swallowed air and bacterial fermentation. Every time you eat, drink, or even swallow saliva, you take in small amounts of air. Most of this is burped out, but a portion travels into the intestines. The second and more significant source is the bacterial microbiome in the large intestine. Trillions of bacteria break down undigested carbohydrates — particularly fibers, sugars, and starches — through fermentation, producing hydrogen, methane, and carbon dioxide as byproducts. These gases accumulate and eventually need to go somewhere.
The Journey Through the Digestive System
Once gas forms in the large intestine, it moves toward the rectum through peristalsis — the wave-like muscular contractions that propel everything through your gut. The internal and external sphincter muscles control when (and whether) the gas is released. Interestingly, the body can partially reabsorb some gases through the intestinal wall into the bloodstream, where they are expelled through the lungs. The gas that is not reabsorbed continues its journey outward — which is where Art-of-Fart comes in.
Is Farting Healthy?
Absolutely. Holding in gas regularly can cause bloating, discomfort, and cramping. The average healthy person produces between 500 ml and 1,500 ml of intestinal gas per day. Variations in frequency are completely normal and depend heavily on diet, gut microbiome composition, and individual digestive speed. A sudden increase in flatulence, particularly when accompanied by pain, blood in stool, or unintended weight loss, may warrant a medical consultation. For most people, however, farting is simply the digestive system working as intended.
The Difference Between a Fart and a Burp
Both are exits for digestive gas, but they come from different locations and have different compositions. Burps release gas primarily from the stomach and esophagus — mostly swallowed air, which is largely odorless nitrogen and oxygen. Farts originate from the large intestine and contain bacterial fermentation gases, including trace amounts of sulfur compounds that are responsible for the characteristic smell. The composition of a fart is roughly 59% nitrogen, 21% hydrogen, 9% carbon dioxide, 7% methane, and 4% oxygen — with less than 1% sulfur compounds doing all the olfactory heavy lifting.
Did You Know?
- The average person farts 14–23 times per day — whether they realize it or not.
- Women and men produce roughly equal amounts of intestinal gas, despite popular belief.
- The word 'fart' has been in the English language since at least the 13th century.
- Holding in gas does not cause it to disappear — it is eventually reabsorbed or released during sleep.
Fun Fact
In 2014, researchers at the University of Exeter found that hydrogen sulfide — the compound responsible for the rotten-egg smell in farts — may actually protect cells from damage and reduce the risk of stroke, heart disease, and dementia when present in tiny amounts. Your fart might literally be saving your life.
Sources
- Levitt, M.D. (1998). Intestinal gas production. New England Journal of Medicine.
- Suarez, F.L. et al. (1997). Insights into human colonic physiology. American Journal of Physiology.