See also "Professional farter". Saaay whaaat?!?

Flatulence is the presence of a mixture of gases in the digestive tract of mammals. Such a mixture of gases is known as flatus, and is expelled from the rectum in a process colloquially known as farting.

Explanation
Flatus is expelled under pressure through the anus, whereby, as a result of the voluntary or involuntary tensing of the anal sphincter, the rapid evacuation of gases from the lower intestine occurs. Essentially this happens when the flatus pressure inside the rectum exceeds the anal sphincter's ability to restrain it. Depending upon the relative state of the sphincter (relaxed/tense) and the positions of the buttocks, this often results in an audible crackling or trumpeting sound, but gas can also be passed quietly. The olfactory components of flatulence include skatole, indole, and sulfurous compounds.[1] The non-odorous gases are mainly nitrogen (ingested), carbon dioxide (produced by aerobic microbes or ingested), and hydrogen (produced by some microbes), as well as lesser amounts of oxygen (ingested) and methane (produced by anaerobic microbes).[2]


[edit] Composition of flatus gases
Nitrogen is the primary gas released. Carbon dioxide is often present, especially in persons who drink carbonated beverages in quantity. Methane and hydrogen, lesser components, are flammable, and so flatus is susceptible to catching fire[citation needed]. Not all humans produce flatus that contains methane. For example, in one study of the feces of nine adults, only five of the samples contained bacteria capable of producing methane.[3] Similar results are found in samples of gas obtained from within the rectum.

The gas released during a flatus event frequently has a foul odor which mainly results from low molecular weight fatty acids such as butyric acid (rancid butter smell) and reduced sulfur compounds such as hydrogen sulfide (rotten egg smell) and carbonyl sulfide that are the result of protein breakdown. The incidence of odoriferous compounds in flatus increases from herbivores, such as cattle, through omnivores to carnivorous species, such as cats or dogs. Flatulence odor can also be caused by the presence of large numbers of microflora bacteria and/or the presence of feces in the rectum.

The major components of the flatus by percentage are:[4]

Nitrogen - 20% - 90%
Hydrogen - 0% - 50%
Carbon Dioxide - 10% - 30%
Oxygen - 0% - 10%
Methane - 0% - 10%

[edit] Mechanism of action
The noises commonly associated with flatulence are caused by the vibration of the anal sphincter, and occasionally by the closed buttocks. The sound varies depending on the tightness of the sphincter muscle and velocity of the gas being propelled, as well as other factors such as water and body fat. The auditory pitch (sound) of the flatulence outburst can also be affected by the anal embouchure. Among humans, flatulence sometimes happens accidentally, such as incidentally to coughing or sneezing; on other occasions, flatulence can be voluntarily elicited by tensing the rectum or "bearing down" and subsequently releasing the anal sphincter, resulting in the expulsion of a flatus. Humans are also known to flatulate during sleep, largely due to the relaxed state of body muscles, which results in the average person flatulating about 10-20 times through any given night.[citation needed]

Flatus is brought to the rectum via peristalsis, which also causes feces to descend from the large intestine, and may cause a similar feeling of urgency and discomfort. Nerve endings in the rectum usually enable individuals to distinguish between flatus and feces, although loose stool can confuse the individual, occasionally resulting in accidental defecation.


[edit] Causes
Intestinal gas is composed of varying quantities of exogenous sources (air that is ingested through the nose and mouth) and endogenous sources (gas produced within the digestive tract). The exogenous gases are swallowed (aerophagia) when eating or drinking or increased swallowing during times of excessive salivation (as might occur when nauseated or as the result of gastroesophageal reflux disease). The endogenous gases are produced either as a by-product of digesting certain types of food, or of incomplete digestion. Anything that causes food to be incompletely digested by the stomach and/or small intestine may cause flatulence when the material arrives in the large intestine due to fermentation by yeast or bacteria normally or abnormally present in the gastrointestinal tract.

Flatulence-producing foods are typically high in certain polysaccharides (especially oligosaccharides such as inulin) and include beans, lentils, dairy products, onions, garlic, scallions, leeks, radishes, sweet potatoes, cashews, Jerusalem artichokes, oats, wheat, yeast in breads, and other vegetables. Cauliflower, Broccoli, cabbage and other cruciferous vegetables that belong to the Brassica family are commonly reputed to not only increase flatulence, but to increase the pungency of the flatus. In beans, endogenous gases seem to arise from complex oligosaccharide (carbohydrates) that are particularly resistant to digestion by mammals, but which are readily digestible by microorganisms that inhabit the digestive tract. These oligosaccharides pass through the upper intestine largely unchanged, and when these reach the lower intestine, bacteria feed on them, producing copious amounts of flatus.[5] In the case of those with lactose intolerance, intestinal bacteria feeding on lactose can give rise to excessive gas production when milk or lactose-containing substances have been consumed.

Interest in the causes of flatulence was spurred by high-altitude flight and the space program; the low atmospheric pressure, confined conditions, and stresses peculiar to those endeavours were cause for concern.[5] In the field of mountaineering, High Altitude Flatus Expulsion was first noticed over two hundred years ago.


[edit] Remedies

[edit] Dietary
Certain spices have been reported to counteract the production of intestinal gas, most notably cumin[citation needed], coriander[citation needed], caraway and the closely related ajwain, turmeric, asafoetida (hing), epazote, and kombu kelp (a Japanese seaweed).[citation needed] Most starches, including potatoes, corn, noodles, and wheat, produce gas as they are broken down in the large intestine. Rice is the only starch that does not cause gas.[6] The amount of water-soluble oligosaccharide in beans that may contribute to production of intestinal gas is reputed to be reduced by a long period of soaking followed by boiling,[citation needed] but at a cost of also leaching out other water-soluble nutrients.[citation needed] Also, intestinal gas can be reduced by fermenting the beans, and making them less gas-inducing, and/or by cooking them in the liquor from a previous batch[citation needed]. Lactobacillus casei and Lactobacillus plantarum have recently been hypothesized as being responsible for this effect.[7] Some legumes also stand up to prolonged cooking, which can help break down the oligosaccharides into simple sugars. Fermentation also breaks down oligosaccharides, which is why fermented bean products such as miso and tofu are less likely to produce as much intestinal gas[citation needed]).

Probiotics (yogurt, kefir, etc.) are reputed to reduce flatulence when used to restore balance to the normal intestinal flora.[8] Yogurt contains Lactobacillus acidophilus which may be useful in reducing flatulence[citation needed]). L. acidophilus may make the intestines more acidic, thus maintaining the natural balance of fermentation processes.[citation needed] L. acidophilus is available in supplements (non-dairy is reputedly best[citation needed]). Prebiotics, which generally are non-digestible oligosaccharides, such as fructooligosaccharide, generally increase flatulence in a similar way as described for lactose intolerance.[citation needed]

Medicinal activated charcoal tablets have also been reported as effective in reducing both odor and quantity of flatus when taken immediately before food that is likely to cause flatulence later.[citation needed]


[edit] Pharmacological
Digestive enzyme supplements may significantly reduce the amount of flatulence caused by some components of foods not being digested by the body and thereby promoting the action of microbes in the small and large intestines. It has been suggested that alpha-galactosidase enzymes, which can digest certain complex sugars, are effective in reducing the volume and frequency of flatus.[9] The enzymes alpha-galactosidase (brands Beano, Bean-zyme), lactase (brand Lactaid), amylase, lipase, protease, cellulase, glucoamylase, invertase, malt diastase, pectinase, and bromelain are available, either individually or in combination blends, in commercial products.

The antibiotic rifaximin, often used to treat diarrhea caused by the microorganism E. coli, may reduce both the production of intestinal gas and the frequency of flatus events.[10]

While not affecting the production of the gases themselves, surfactants (agents which lower surface tension) can reduce the disagreeable sensations associated with flatulence, by aiding the dissolution of the gases into liquid and solid fecal matter.[citation needed] Preparations containing simethicone reportedly operate by promoting the coalescence of smaller bubbles into larger ones more easily passed from the body, either by burping or flatulence. Such preparations do not decrease the total amount of gas generated in or passed from the colon, but make the bubbles larger and thereby allowing them to be passed more easily.[citation needed]

Often it may be helpful to ingest small quantities of acidic liquids with meals, such as lemon juice or vinegar, to stimulate the production of gastric hydrochloric acid. In turn, acid ingestion may increase normal gastric enzyme and acid production, facilitating normal digestion and perhaps limiting intestinal gas production. Ingestion of bromelain- or papain-containing supplements (such as pineapple or papaya, respectively,) may be helpful.[citation needed]

Odor from flatulence, caused by the intestinal bacteria called microflora in the bowel, can be treated by taking bismuth subgallate (brand Devrom). Bismuth subgallate is commonly used by individuals who have had ostomy surgery, bariatric surgery, fecal incontinence and irritable bowel syndrome.[11][12]


[edit] Post-Release
In 1998, Chester "Buck" Weimer of Pueblo, Colorado, USA received a patent for the first undergarment that contained a replaceable charcoal filter. The undergarments are air-tight and provide a pocketed escape hole in which a charcoal filter can be inserted.[13]

A similar product was released in 2002, but rather than an entire undergarment, consumers are able to purchase an insert similar to a pantiliner that contains activated charcoal.[14] The inventors, Myra and Brian Conant of Mililani, Hawaii, USA still claim on their website to have discovered the undergarment product in 2002 (8 years after Chester Weimer filed for a patent for his product), but states that their tests "concluded" that they should release an insert instead.[15]


[edit] Health effects
As a normal body function, the action of flatulence is an important signal of normal bowel activity and hence is often documented by nursing staff following surgical or other treatment of patients. However, symptoms of excessive flatulence can indicate the presence of irritable bowel syndrome or some other organic disease. In particular, the sudden occurrence of excessive flatulence together with the onset of new symptoms provide reason for seeking further medical examination.

Flatulence is not poisonous; it is a natural component of various intestinal contents. However, discomfort may develop from the build-up of gas pressure. In theory, pathological distension of the bowel, leading to constipation, could result if a person holds in flatulence.

Not all flatus is released from the body via the anus. When the partial pressure of any gas component of the intestinal lumen is higher than its partial pressure in the blood, that component enters into the bloodstream of the intestinal wall by the process of diffusion. As the blood passes through the lungs this gas can diffuse back out of the blood and be exhaled. If a person holds in flatus during daytime, it will often be released during sleep when the body is relaxed. Some flatus can become trapped within the feces during its compaction and will exit the body, still contained within the fecal matter, during the process of defecation.


[edit] Environmental impact

The flatulence of cows is only a small portion of global methane releaseFlatulence is often blamed as a significant source of greenhouse gases owing to the erroneous belief that the methane released by livestock is in the flatus.[16] While livestock account for around 20% of global methane emissions,[17] 90 to 95% of that is released by exhaling or burping.[18] This means only 1–2% of global methane emissions come from livestock flatus.


[edit] Social context
In many cultures, human flatulence in public is regarded as embarrassing and repulsive, even to the point of being a taboo subject. People will often strain to hold in the passing of gas when in polite company, or position themselves to conceal the noise and smell. However, when unsuccessful it creates added embarrassment as in the process of concealment one may draw attention giving clue to the identity of the person responsible. In other cultures it may be no more embarrassing than coughing.

Flatulence is a potential source of humor, either due to the foul smell or the sounds produced. Some find humour in flatulence ignition, which is possible due to the presence of flammable gases such as hydrogen and methane, though the process can result in burn injuries to the rectum, anus and surrounding buttocks.

While the act of bypassing flatus is generally considered to be an unfortunate occurrence in public settings, flatulence may, in casual circumstances, be used as either a humorous supplement to a joke, or as a comic activity in and of itself.


[edit] Literature and the arts
Trivia sections are discouraged under Wikipedia guidelines.
The article could be improved by integrating relevant items and removing inappropriate ones.

See also: Flatulence humor
French singer Serge Gainsbourg wrote a novella, Evguenie Sokolov, about a visual artist who farts to create artworks. The book may be unequalled in its descriptions of the act.
In Roald Dahl's The BFG, the giant teaches Sophie about the joys of "whizzpopping" (farting). In the book, whizpopping is caused by taking the soda-like drink Frobscottle, which fizzes downward, and causes imbibers to pass wind rather than to burp.
In St. Augustine's The City of God, Augustine, not otherwise noted for his levity, makes mention of men who "have such command of their bowels, that they can break wind continuously at will, so as to produce the effect of singing." That mankind in general has lost this ability he attributes to the first sin of Adam and Eve and its consequences with respect to body control. (The City of God Against the Pagans, ed and trans Philip Levine (Cambridge, MA: Harvard University Press, 1966), XIV.24. St Augustine's observation would be emulated in the nineteenth century by the performer Le Pétomane who could fart the French national anthem, La Marseillaise.
Mr. Methane carries on Le Pétomane's tradition today.
In the second verse of the traditional English round "Sumer Is Icumen In" comes the line "Bulluc sterteþ, bucke uerteþ" often translated as "The bullock jumps, the billy-goat farts". This would make it the earliest recorded use of the word fart, although uerteþ could equally mean gambol or cavort.[19]
Benjamin Franklin was said to have written a work entitled The Technique of Farting.[20]
In Dante's Divine Comedy, the last line of Inferno Chapter XXI reads: ed elli avea del cul fatto trombetta ("and he made a trumpet of his buttocks"), in the last example the use of this natural body function underlined a demoniac condition.
Friedrich Dedekind's 16th century work, Grobianus et Grobiana, appeared in England in 1605 as The Schoole of Slovenrie: Or, Cato turnd wrong side outward, published by one "R.F.". The "Schoole" taught its students that holding back the desire to urinate, fart, and vomit was bad for one's health; thus, one has to indulge freely in all three activities.
Montaigne, in his essay Of the Force of Imagination, includes a discussion of flatulence. Of 'the vessels that serve to discharge the belly', he writes "I myself knew one so rude and ungoverned, as for forty years together made his master vent with one continued and unintermitted outbursting, and 'tis like will do so till he die of it".[21]
In the Teenage Mutant Ninja Turtles television, theatrical, and comic series, the youngest of the turtles, Michelangelo, often farts in an attempt to annoy his older brothers and as an act of comic relief.
In Emile Zola's La Terre (The Earth, the 15th volume of the series Les Rougon-Macquart), the eldest Fouan son can fart at will and keeps winning free drinks by betting on his skill.
In James Joyce's Ulysses, the main character (Leopold Bloom) breaks wind in the "Sirens" chapter of the book.[22]
In the United States, The Gas We Pass is a popular children's book about flatulence.
The film Wet Hot American Summer features a boy lighting a fart as an act in a talent show. Additionally, the film's DVD features an optional "fart track" that adds flatulent noises to the film's audio.
In the film "The Lion King 1 1/2" Pumbaa releases a massive fart which causes a few animals to collapse and also causes the animals in front to think they are bowing.
An episode of MythBusters featured myths about flatulence and determined the chemical composition of a typical flatus.
Brent Spiner's character in the movie The Master of Disguise suffered from uncontrolled flatulence any time he broke into a fit of evil laughter.
The lighting of flatulence is used as a device of social acceptance in a dream sequence of the film Dumb and Dumber.
In the movie Mystery Men, "The Spleen" (played by Paul Reubens) is a "superhero" who, due to a gypsy curse, can aim his highly noxious flatulence with deadly precision.
The animated series South Park features two comedians, named Terrance and Philip, who star in a television program the main characters frequently watch. Their act features a lot of flatulence which causes a great deal of offence to the more conservative residents of South Park.
A scene in the comedy film Blazing Saddles in which a posse of cowboys sitting around a camp fire eat baked beans, causing extreme flatulence. Curiously, the farting sounds were removed from some TV showings of this film[citation needed], making it somewhat incomprehensible.
The film ¡Ay, Carmela! has a theater scene in which the main actor plays a role of a fart-man. He is requested by the audience to produce many farts.
In the movie Beavis and Butthead Do America one of the drifters in the desert remarks "Do you wanna see something really cool" and then proceeds to fart into a campfire igniting a nuclear bomb-like mushroom cloud.
"I fart in your general direction!" was a taunt delivered from the top of a castle wall to King Arthur and his company in Monty Python and the Holy Grail.
In the movie Skate or Die Tryin, the main character, Gil, refers to a CD as "Uncontrollable Flatulence." This is factually incorrect, as the real title of the CD is Uncontrollable Fatulence.
In an episode of Family Guy, Peter Griffin and Michael Moore use flatulence to engage in a sort of dueling banjoes style musical piece. In another episode, Peter tries to hide his flatulence by coughing and talking over it during a PTA meeting, humorously trying to cover one particularly long fart with a drawn out word. (Teacher: Do you have something to share with us, Mr. Griffin?" Peter: (Farts) Nooooooooooooooo. (Farts again) No." In yet another episode, Peter hires Michael McDonald to sing everything he says. (Peter: "Oh, no, not this guy again." McDonald repeats. Peter:(Farts) McDonald (sings)Fa-ar-rt.)
In the Shrek films, Shrek is known for his flatulence problem. In the first film, he farts in the water to catch fish. In the second film, he accidentally farts in the mud sauna with Fiona, and becomes embarrassed, until Fiona decides to fart with him.

[edit] Curiosities
Trivia sections are discouraged under Wikipedia guidelines.
The article could be improved by integrating relevant items and removing inappropriate ones.

Le Pétomane "the Fartiste" a famous French performer in the nineteenth century as well as many professional farters before him did flatulence impressions and held shows. Mel Brooks named his fictional governor (played by himself) William J. LePetomaine in the Western spoof film Blazing Saddles.
Emperor Claudius passed a law legalizing farting at banquets out of concern for people's health.[23] There was a widespread misconception that a person could be poisoned by retaining flatus.
Flavius Josephus reports in The Wars of the Jews that a Roman soldier raised his clothes and farted at the Passover. This profane act so enraged the Jews that it caused a riot, during which many thousands were killed.[24]
An apocryphal story about Edward de Vere, Earl of Oxford is that he farted while swearing loyalty to Queen Elizabeth I and consequently went into self-imposed exile for seven years. After his return, the Queen was reported to have reassured de Vere: "My Lord, I had quite forgotten the fart." (John Aubrey, Brief Lives)
Bulgaria regularly holds annual Flatulance competitions, based on internet votes. The winner in 2006 & 2007 was a famous Mafia linked personality called Maria Doychinova. Local media suggested, rather unkindly, that her bad breath was actually worse than her Flatulance.
In August 2005, New Scientist magazine reported that inventors Michael Zanakis and Philip Fermano had been awarded a US patent (U.S. Patent 6,055,910 ) for a "toy gas-fired missile and launcher assembly". The abstract of the patent makes it clear that this is, in fact, a fart-powered rocket:
"A ... missile is composed of a soft head and a tail extending therefrom formed by a piston. The piston is telescoped into the barrel of a launcher having a closed end on which is mounted an electrically activated igniter, the air space between the end of the piston and the closed end of the barrel defining a combustion chamber. Joined to the barrel, and communicating with the chamber therein, is a gas intake tube having a normally closed inlet valve. To operate the assembly, the operator places the inlet tube with its valve open adjacent to his anal region, from which a colonic gas is discharged. The piston is then withdrawn to a degree producing a negative pressure to inhale the gas into the combustion chamber to intermix with the air therein to create a combustible mixture. The igniter is then activated to explode the mixture in the chamber and fire the missile into space."
British inventors have also patented fart-related ideas, such as "A fart collecting device," which includes a drawing of the invention deployed and ready for action, with helpful numbers to identify the various components. "It comprises a gas-tight collecting tube 10 for insertion into the rectum of the subject. The tube 10 is connected to a gas-tight collecting bag (not shown). The end of the tube inserted into the subject is apertured and covered with a gauze filter and a gas permeable bladder 28."
Mambo Graphics, an Australian surfwear label, features the iconic "Farting Dog" design [1] in its lineup. Here the flatulence is depicted as a musical note emanating from the dog's backside.
Former Canadian Prime Minister Pierre E. Trudeau was (and still is by those who remember him) referred to in Quebec as "petit pét", or "little fart" because of his initials (PET). This could be considered a mildly affectionate or highly derogatory nickname, depending on the tone. Those who enjoy a bilingual pun also note that this usage gives new meaning to having a pet name for someone.
Charles Darwin, scientist and originator of the theory of evolution by natural selection, was severely troubled by flatulence in his later years.[25] The source for this is Darwin's diary. However, around the time of Darwin's illness, flatulence meant belching (ref. OED); it hadn't yet evolved into the meaning it has today.
Moving intestinal gas may provide calculation and imaging errors in radiology and nuclear medicine combined procedures of PET/CT and SPECT/CT due to the fact that in the few minutes between CT and emission imaging the gas may have moved to a different portion of the bowel; colonic gas was referred to as "imminent social disaster" at the 2001 SNM meeting, where the new technique was presented for the first time on a large scale.




[edit] See also
Professional farter
Borborygmus
Vaginal flatulence
The Gas We Pass
Fart lighting
Le Petomane