|
|
| Line 2: |
Line 2: |
| {{Flatulence}} | | {{Flatulence}} |
| {{CMG}} | | {{CMG}} |
| ==Overview== | | ==[[Flatulence overview|Overview]]== |
|
| |
|
| '''Flatulence''' is the presence of a mixture of gases known as '''flatus''' in the [[gastrointestinal tract|digestive tract]] of [[mammals]] expelled from the [[rectum]]. It is more commonly known as '[[fart]]ing', 'passing gas', or 'passing wind' ([[UK]]).
| | ==[[Flatulence historical perspective|Historical Perspective]]== |
|
| |
|
| == Explanation == | | ==[[Flatulence classification|Classification]]== |
| 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. Depending upon the relative state of the [[sphincter]] (relaxed/tense) and the positions of the [[buttock]]s, 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 [[sulfur]]ous compounds.<ref>{{cite web
| |
| |url=http://www.patient.co.uk/showdoc/40000086/
| |
| |title=Flatulence, wind and bloating
| |
| |publisher=Patient UK | |
| |accessdate=2006-12-11
| |
| }}</ref> The non-odorous gases are mainly [[nitrogen]] (ingested), [[carbon dioxide]] (produced by [[aerobic organism|aerobic microbes]] or ingested), and [[hydrogen]] (produced by some microbes and consumed by others), as well as lesser amounts of [[oxygen]] (ingested) and [[methane]] (produced by [[anaerobic organism|anaerobic microbe]]s).<ref>{{cite journal| author=Suarez F| coauthors=Furne J, Springfield J, Levitt M| title=Insights into human colonic physiology obtained from the study of flatus composition| journal=Am J Physiol| year=1997| volume=272 (5 Pt 1)| pages=G1028–33}}</ref> Odors result from trace amounts of other components (often containing [[sulfur]] compounds, see below).
| |
|
| |
|
| == Composition of flatus gases == | | ==[[Flatulence pathophysiology|Pathophysiology]]== |
| [[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]]. 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.<ref>{{cite journal| author=Miller TL| coauthors=Wolin MJ, de Macario EC, Macario AJ| title=Isolation of Methanobrevibacter smithii from human feces| journal=Appl Environ Microbiol| year=1982| volume=43(1)| pages=227–232}}</ref> 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]] ([[Rancidity|rancid]] [[butter]] smell) and [[redox|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 [[cat]]s 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]].
| | ==[[Flatulence causes|Causes]]== |
|
| |
|
| The major components of the flatus by percentage are:<ref>{{cite web
| | ==[[Flatulence differential diagnosis|Differentiating Flatulence from other Diseases]]== |
| | title =Human Digestive System
| |
| | work =Encyclopedia Britannica
| |
| | url =http://www.britannica.com/eb/article-45361/human-digestive-system#294193.hook
| |
| | accessdate = 2007-08-22 }}</ref>
| |
|
| |
|
| * [[Nitrogen]] - 20% - 90%
| | ==[[Flatulence epidemiology and demographics|Epidemiology and Demographics]]== |
| * [[Hydrogen]] - 0% - 50%
| |
| * [[Carbon Dioxide]] - 10% - 30%
| |
| * [[Oxygen]] - 0% - 10%
| |
| * [[Methane]] - 0% - 10%
| |
|
| |
|
| ==Mechanism of action== | | ==[[Flatulence risk factors|Risk Factors]]== |
| The [[noise]]s commonly associated with flatulence are caused by the [[oscillation|vibration]] of the [[anus|anal]] [[sphincter]], and not by the [[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, farting sometimes happens accidentally, such as incidentally to [[cough]]ing or [[sneezing]]; on other occasions, farting can be voluntarily elicited by tensing the [[rectum]] or "bearing down" and subsequently releasing the anal sphincter. 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.
| |
|
| |
|
| 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]].
| | ==[[Flatulence natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
|
| |
|
| ==Causes == | | ==Diagnosis== |
| 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 (biochemistry)|fermentation]] by [[yeast]] or [[bacteria]] normally or abnormally present in the [[gastrointestinal tract]].
| | [[Flatulence diagnostic criteria|Diagnostic Criteria]] | [[Flatulence history and symptoms|History and Symptoms]] | [[Flatulence physical examination|Physical Examination]]| [[Flatulence laboratory findings|Laboratory Findings]] | [[Flatulence abdominal x ray|Abdominal X Ray]] | [[Flatulence CT|CT]] | [[Flatulence MRI|MRI]] | [[Flatulence ultrasound|Ultrasound]] | [[Flatulence other imaging findings|Other Imaging Findings]] | [[Flatulence other diagnostic studies|Other Diagnostic Studies]] |
|
| |
|
| Flatulence-producing foods are typically high in certain [[polysaccharide]]s (especially [[oligosaccharides]] such as [[inulin]]) and include [[bean]]s, [[lentil]]s, [[dairy product]]s, [[onion]]s, [[garlic]], [[scallion]]s, [[leek]]s, [[radish]]es, [[sweet potato]]es, [[cashew]]s, [[Jerusalem artichoke]]s, [[oat]]s, [[wheat]], [[yeast]] in [[bread]]s, and other [[vegetable]]s. [[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]] ([[carbohydrate]]s) that are particularly resistant to digestion by mammals, but which are readily digestible by [[microorganisms]] that inhabit the [[digestive tract]]. These [[oligosaccharide]]s pass through the upper [[intestine]] largely unchanged, and when they reach the lower [[intestine]], [[bacteria]] feed on them, producing copious amounts of flatus.<ref name="McGee">{{cite book| last=McGee| first=Harold| title=[[On Food and Cooking]]| publisher=Scribner| year=1984| id=ISBN 0-684-84328-5| pages=257–8}}</ref> 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.
| | ==Treatment== |
| | [[Flatulence medical therapy|Medical Therapy]] | [[Flatulence surgery|Surgery]] | [[Flatulence primary prevention|Primary Prevention]] | [[Flatulence secondary prevention|Secondary Prevention]] | [[Flatulence cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Flatulence future or investigational therapies|Future or Investigational Therapies]] |
|
| |
|
| 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.<ref name="McGee"/>
| | == Case Studies == |
| | | [[Flatulence case study one|Case #1]] |
| ==Remedies== | | '''==External links== |
| ===Dietary===
| |
| Certain [[spice]]s have been reported to counteract the production of intestinal gas, most notably [[cumin]], [[coriander]], [[caraway]] and the closely related [[ajwain]], [[turmeric]], [[asafoetida]] (hing), [[epazote]], and [[kombu]] [[kelp]] (a Japanese [[seaweed]]). 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.<ref>''[http://digestive.niddk.nih.gov/ddiseases/pubs/gas/index.htm Gas in the Digestive Tract]'' a publication of National Digestive Diseases Information Clearinghouse, part of the US National Institute of Health</ref> 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, but at a cost of also leaching out other water-soluble nutrients. 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. ''[[Lactobacillus casei]]'' and ''[[Lactobacillus plantarum]]'' have recently been hypothesized<!-- Never, never, NEVER EVER use the word "PROVEN" in a scientific article. Science hypothesizes, tests hypotheses, and accepts hypotheses that have not yet been DISproven. Science never proves anything! --> as being responsible for this effect.<ref>{{cite web|title=Study shows secret to gas-free beans|url=http://web.archive.org/web/20060502110835/http://reuters.myway.com/article/20060426/2006-04-26T170153Z_01_N25328545_RTRIDST_0_ODD-BEANS-DC-DC.html|date=2006-04-26|accessdate=2007-09-10}}</ref> Some [[legume]]s also stand up to prolonged cooking, which can help break down the oligosaccharides into simple sugars. [[fermentation (food)|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.
| |
| | |
| [[Probiotic]]s ([[yogurt]], [[kefir]], etc.) are reputed to reduce flatulence when used to restore balance to the normal intestinal flora.<ref>Rubin J. and J. Brasco, ''Restoring Your Digestive Health'' (2003).</ref> Yogurt contains ''[[Lactobacillus acidophilus]]'' which may be useful in reducing flatulence. ''[[Lactobacillus acidophilus|L. acidophilus]]'' may make the intestines more acidic, thus maintaining the natural balance of fermentation processes. ''[[Lactobacillus acidophilus|L. acidophilus]]'' is available in supplements (non-dairy is reputedly best. [[Prebiotics]], which generally are non-digestible oligosaccharides, such as [[fructooligosaccharide]], generally increase flatulence in a similar way as described for lactose intolerance.
| |
| | |
| Medicinal [[Activated carbon|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.
| |
| | |
| ===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.<ref>{{cite journal| author=Ganiats TG| coauthors=Norcross WA, Halverson AL, Burford PA, Palinkas LA| title=Does Beano prevent gas? A double-blind crossover study of oral alpha-galactosidase to treat dietary oligosaccharide intolerance| journal=J Fam Pract| year=1994| volume=39| pages=441–445}}</ref> The [[enzymes]] [[alpha-galactosidase]] (brands [[Beano (dietary supplement)|Beano]], Bean-zyme), [[lactase]] (brand Lactaid), [[amylase]], [[lipase]], [[protease]], [[cellulase]], [[Amylase#γ-Amylase|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.<ref>{{cite journal| author=Di Stefano M| coauthors=Strocchi A, Malservisi S, Veneto G, Ferrieri A, Corazza GR| title=Non-absorbable antibiotics for managing intestinal gas production and gas-related symptoms| journal=Aliment Pharmacol Ther| year=2000| volume=14| pages=1001–1008}}</ref>
| |
| | |
| 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. Preparations containing [[simethicone]] reportedly operate by promoting the coalescence of smaller bubbles into larger ones more easily passed from the body, either by [[burp]]ing 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.
| |
| | |
| Often it may be helpful to ingest small quantities of [[acid]]ic 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.
| |
| | |
| [[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]].<ref>{{cite journal| author=Turnbull G| title=The Ostomy Files:The Issue of Oral Medications and a Fecal Ostomy| journal=Ostomy/Wound Management|year=2005| volume=51| pages=14-16}}</ref><ref>{{cite web |url=http://www.cancer.org/docroot/CRI/content/CRI_2_6x_Colostomy.asp|title=Colostomy Guide|date=2006-01-04|accessdate=2007-09-10}}</ref>
| |
| | |
| ===Post-Release===
| |
| In [[1998]], [[Weimer, Chester|Chester "Buck" Weimer]] of [[Pueblo, Colorado]], [[USA]] received a patent for the first [[undergarment]] that contained a replaceable [[charcoal filter]]. The undergarments are [[Hermetic seal|air-tight]] and provide a pocketed [[path of least resistance|escape hole]] in which a charcoal filter can be inserted.<ref name="weimer">{{cite web |last=Weimer |first=Chester |url=http://patft.uspto.gov/netacgi/nph-Parser?TERM1=5593398&u=/netahtml/srchnum.htm&Sect1=PTO1&Sect2=HITOFF&p=1&r=0&l=50&f=S&d=PALL|title= Protective underwear with malodorous flatus filter|date=1997-01-14|accessdate=2007-07-27}}</ref>
| |
| | |
| 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.<ref>{{cite web |last= Conant |first= Brian J. |coauthors= Myra M. Conant |url=http://patft.uspto.gov/netacgi/nph-Parser?TERM1=6313371&u=/netahtml/srchnum.htm&Sect1=PTO1&Sect2=HITOFF&p=1&r=0&l=50&f=S&d=PALL|title= Flatulence deodorizer |date=2001-11-06|accessdate=2007-09-10}}</ref> The inventors, [[Myra Conant|Myra]] and [[Brian Conant]] of [[Milihani, 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.<ref>{{cite web|url=http://www.flat-d.com/american-inventor.html|title=www.flat-d.com/american-inventor.html|title=Flat-D Innovations Inc.: About the American Inventor|accessdate=2007-09-10}}</ref>
| |
| | |
| ==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 flatus.
| |
| | |
| Not all flatus is released from the body via the anus. When the [[partial pressure]] of any gas component of the intestinal [[lumen (anatomy)|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]].
| |
| | |
| ==Environmental impact==
| |
| Flatulence is often blamed as a significant source of [[greenhouse gas]]es owing to the erroneous belief that the methane released by [[livestock]] is in the flatus.<ref>[http://www.abc.net.au/southqld/stories/s1560903.htm?backyard ABC Southern Queensland: "Could skippy stop cows farting and end global warming?"] Friday, 3 February 2006. Example of error. Although the article doesn't specify whether the methane is released by flatulence or eructation, it appears the headline-writer assumes it's through flatulence.</ref> While livestock account for around 20% of global [[methane]] emissions,<ref>{{cite web| url=http://www.newscientist.com/article.ns?id=dn6431| title=Burp vaccine cuts greenhouse gas| first=Rachel| last=Nowak| date=[[September 24]], [[2004]]| work=New Scientist}}</ref> 90 to 95% of that is released by [[breath|exhaling]] or [[burping]].<ref>[http://www.mycattle.com/health/dsp_health_article.cfm?storyid=10045 "Bovine belching called udderly serious gas problem - Global warming concerns spur effort to cut methane."] By Gary Polakovic. ''Los Angles Times'', Sunday, July 13, 2003.</ref> This means only 1–2% of global methane emissions come from livestock flatus.
| |
| | |
| ==Social context==
| |
| In many [[culture]]s,
| |
| 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.
| |
| In other cultures it may be no more embarrassing than [[cough]]ing.
| |
| | |
| Flatulence is a potential source of humor, either due to the foul smell or the sounds produced. Some find humour in [[Fart lighting|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 farting is generally considered to be an unfortunate occurrence in public settings, a flatus may, in casual circumstances, be used as either a humorous supplement to a joke, or as a comic activity in and of itself.
| |
| | |
| ''The History of Farting'', by Benjamin Bart, is a collection of assorted [[Limerick (poetry)|limericks]], facts, and blurbs on farting, while ''Who Cut the Cheese: A Cultural History of the Fart'', by Jim Dawson, gives a more complete cultural discussion of the historical and social significance of farting.
| |
| | |
| ==See also==
| |
| *[[Professional farter]]
| |
| *[[Borborygmus]]
| |
| *[[Vaginal flatulence]]
| |
| *[[The Gas We Pass]]
| |
| *[[Fart lighting]]
| |
| *[[Shart (slang)|Shart]]
| |
| | |
| ==References==
| |
| {{wikisourcepar|Harper%27s_New_Monthly_Magazine/Vol. XLIV/No._261/February_1872/Editor%27s_Scientific_Record/Cure_of_Flatulence|A cure for flatulence from 1872}}
| |
| {{reflist|2}}
| |
| | |
| ===Nontechnical resources===
| |
| * {{cite book | author = Franklin, Benjamin | editor = Japikse, Carl (Ed.) | title = Fart Proudly | publisher = Frog Ltd/Blue Snake | year = 2003 | edition = (Reprint) | id = ISBN 1-58394-079-0 }}
| |
| * {{cite book | author = Dawson, Jim | title = Who Cut the Cheese?: A Cultural History of the Fart | publisher = Ten Speed Press | year = 1999 | id = ISBN 1-58008-011-1 }}
| |
| * {{cite book | author = Dawson, Jim | title = Blame it on the Dog: A Modern History of the Fart | publisher = Ten Speed Press | year = 2006 | id = ISBN 1-58008-751-5 }}
| |
| * {{cite book | author = D. von Schmausen | title = Official Rules, New World Odor International Freestyle Farting Championship | publisher = LULU | year 2002 }}
| |
| | |
| ==External links== | |
| *[http://www.fartsurvey.com The Farting Survey (fartsurvey.com)] - a comprehensive, worldwide survey about farts and farting. | | *[http://www.fartsurvey.com The Farting Survey (fartsurvey.com)] - a comprehensive, worldwide survey about farts and farting. |
| *[http://www.merck.com/mmpe/sec02/ch008/ch008d.html The Merck Manual of Diagnosis and Therapy, Gas] | | *[http://www.merck.com/mmpe/sec02/ch008/ch008d.html The Merck Manual of Diagnosis and Therapy, Gas] |
| Line 117: |
Line 37: |
| *[http://www.fartnoises.info Fart Sounds] - frequently updated flog (fart+blog) dealing with all aspects of flatulence. | | *[http://www.fartnoises.info Fart Sounds] - frequently updated flog (fart+blog) dealing with all aspects of flatulence. |
| *[http://www.redpoop.com/body_gas/excessive_gas.html Excessive Gas] | | *[http://www.redpoop.com/body_gas/excessive_gas.html Excessive Gas] |
|
| |
|
| |
|
| |
|
| <sub></sub> | | <sub></sub> |