Flatulence Facts

Beneath the laughter, farting is a natural and fascinating biological process. Here you’ll find science‑backed trivia about flatulence, along with practical tips to impress (or disgust) your friends. All facts are sourced from credible medical and scientific literature so you know you’re reading the truth about toots.

What Causes Farts?

Flatulence forms when bacteria in your large intestine break down food that your own digestive system can't handle. This process produces gases that need to exit your body. Without passing gas through burping or farting, we'd risk serious discomfort. Belching releases air from the stomach and esophagus, while farting releases gas generated lower down in the digestive tract.

The digestive process begins when you swallow air while eating or drinking - this accounts for about 50% of intestinal gas. The remaining gas comes from bacterial fermentation of undigested carbohydrates in your colon. Your gut microbiome contains trillions of bacteria that produce hydrogen, methane, and carbon dioxide as they break down food. Certain sugars like raffinose (found in beans) and lactose (in dairy) are particularly difficult for humans to digest, leading to increased gas production.

How Often Do We Fart?

If you think you're alone in your flatulence, think again. Adults produce around two pints of gas each day and fart an average of 14 times. Some days can be a bit windier – up to 21 toots per day is still normal.

Interestingly, men and women fart at roughly equal rates, despite common stereotypes. The frequency varies based on diet, gut health, and individual microbiome composition. Most flatulence occurs during bowel movements or within an hour after meals. During sleep, the anal sphincter relaxes slightly, which is why morning farts are often more noticeable. Athletes may experience increased flatulence due to swallowing more air during heavy breathing and changes in digestion during exercise.

Why Do Some Farts Smell?

Surprisingly, 99 percent of the gas in your average fart is made up of odorless gases like nitrogen, oxygen, carbon dioxide, hydrogen and methane. The infamous stench comes from sulfur compounds created when gut microbes digest foods rich in sulfur – think broccoli, cauliflower, Brussels sprouts and dairy. Other foods linked to more gas and smell include beans, onions, cabbage, eggs and prunes.

The main culprits for fart odor are hydrogen sulfide (rotten egg smell), methanethiol (rotten cabbage), and dimethyl sulfide (sweet but unpleasant). These compounds are so potent that humans can detect them at concentrations as low as 0.0047 parts per million. Temperature affects smell intensity - warmer farts smell stronger because heat helps volatile compounds evaporate faster. Protein-rich diets tend to produce smellier farts due to higher sulfur content, while carbohydrate-heavy diets create more volume but less odor.

Can You Hold in a Fart?

Many of us have clenched our cheeks hoping to avoid embarrassment, but you can’t hold in a fart forever. Gas will eventually find its way out – and it might be noisier if you wait. In rare cases, holding gas too long can cause it to be reabsorbed into your bloodstream and exit through your mouth. Best to let it go!

Fart Vocabulary

Ever hear someone talk about flatus? That’s the medical term for a fart, borrowed from Latin. The rumbling in your stomach when gas builds up is called borborygmus. Across cultures there are hundreds of creative names for passing gas – cutting the cheese, breaking wind, letting one rip, blowing a raspberry and more.

Medical professionals use specific terminology: flatulence (the condition of having gas), flatus (the gas itself), and flatulent (describing someone who has gas). The act of passing gas is called flatulating. Different fart sounds have names too - the "slider" (silent), the "popper" (short and loud), and the "ripper" (long and loud). In Victorian times, people used euphemisms like "breaking society" or "dropping one's linen." Modern slang continues to evolve with terms like "crop dusting" (farting while walking) and "Dutch oven" (farting under blankets).

Historical Fart Facts

Humans have found farts funny for millennia. The world’s oldest recorded joke, dating back to 1900 BCE, is a fart joke. Even great writers like Shakespeare and Chaucer laced their work with flatulent humour. In modern times, politicians and authors have used fart jokes to lighten serious topics.

The ancient Sumerian joke goes: "Something which has never occurred since time immemorial; a young woman did not fart in her husband's lap." Roman Emperor Claudius allegedly considered passing a law to legalize farting at banquets for health reasons. In medieval times, professional flatulists like Roland the Farter entertained royal courts - he received a manor house for his annual Christmas performance. Benjamin Franklin wrote a satirical essay titled "Fart Proudly" in 1781, proposing scientific study of flatulence. Japanese culture even has "he-gassen" (fart battle) scrolls from the Edo period depicting people fighting with their gas.

When to See a Doctor

Passing gas is normal, but excessive flatulence paired with abdominal pain, changes in bowel habits or severe bloating may signal digestive issues. Conditions like lactose intolerance, celiac disease or irritable bowel syndrome can increase gas production. If you're worried about your gut, seek medical advice.

Red flags include sudden increases in gas frequency (over 25 times daily), foul-smelling gas accompanied by weight loss, bloody stools, or persistent abdominal pain. These symptoms could indicate small intestinal bacterial overgrowth (SIBO), inflammatory bowel disease, or malabsorption disorders. Food intolerances are common culprits - keeping a food diary can help identify triggers. Some medications like antibiotics, laxatives, and fiber supplements can also increase gas production. A gastroenterologist can perform breath tests, stool analyses, or endoscopy to diagnose underlying conditions.

References

This page summarises information from credible sources including a Houston Methodist article on flatulence and an entertaining Mental Floss list of fart facts. Check out those articles for more detail.

The Science of Fart Sounds

The sound of a fart depends on several factors: the amount of gas, the force of expulsion, and the tightness of the anal sphincter muscles. Higher pitched farts indicate a tighter sphincter, while lower sounds come from more relaxed muscles. The velocity of gas exit can reach up to 10 feet per second. Bubbles passing through liquid (common with diarrhea) create distinctive popping sounds. Body position also affects acoustics - sitting compresses the buttocks, often amplifying the sound.

Farts in Space and Extreme Environments

Astronauts face unique flatulence challenges in zero gravity where gas doesn't naturally rise. NASA has studied this extensively because methane and hydrogen are flammable in spacecraft's oxygen-rich environment. Astronaut diets are carefully planned to minimize gas production. Deep-sea divers experience the opposite problem - increased pressure can trap gas, causing painful bloating during ascent. Mountain climbers often report increased flatulence at high altitudes due to lower atmospheric pressure allowing intestinal gas to expand.

Animal Flatulence Facts

Humans aren't the only creatures that fart. Cows produce 250-500 liters of methane daily, contributing significantly to greenhouse gases. Termites collectively produce more methane than all other natural sources combined. Some animals like birds, sloths, and most fish don't fart at all due to different digestive systems. The Sonoran coral snake uses farting as a defense mechanism, producing a popping sound to scare predators. Manatees use flatulence to control buoyancy while swimming. Interestingly, kangaroos produce virtually no methane thanks to special gut bacteria that scientists are studying for potential agricultural applications.

References

This page summarises information from credible sources including Houston Methodist health articles, Johns Hopkins Medicine digestive health resources, gastroenterology journals, NASA space physiology studies, and peer-reviewed research on gut microbiome and flatulence. Additional insights come from the American Gastroenterological Association and various scientific studies on intestinal gas production and composition.