View source for Flatulence

{{Short description|Bodily function of expelling intestinal gas out of the anus}}
{{Use mdy dates|date=August 2015}}
{{Infobox medical condition (new)
| name          = Flatulence
| synonyms      = Passing gas, farting, cutting the cheese, breaking wind, cutting one loose, ripping one, guffing, chuffing
| image         = Illustration of man suffering from wind. Wellcome L0005360.jpg
| alt           = 
| caption       = Illustration of man suffering from "wind"
| pronounce     = 
| field         = [[w:Gastroenterology|Gastroenterology]]
| symptoms      = 
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| causes        = 
| risks         = 
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'''Flatulence''' is defined in the medical literature as "flatus expelled through the [[anus]]" or the "quality or state of being flatulent",<ref>{{cite dictionary |url=http://www.merriam-webster.com/dictionary/flatulence |title=Flatulence |dictionary=[[Merriam-Webster]] |access-date=August 24, 2015}}</ref> which is defined in turn as "marked by or affected with gases generated in the intestine or stomach; likely to cause digestive flatulence".<ref>{{cite dictionary |url=http://www.merriam-webster.com/medlineplus/flatulent |title=Medical Dictionary: Flatulent |dictionary=[[Merriam-Webster]] |access-date=August 24, 2015}}</ref> The root of these words is from the Latin {{lang|la|flatus}} – "a blowing, a breaking wind".<ref>{{cite dictionary |url=http://www.etymonline.com/index.php?term=flatulent |title=Flatulent |dictionary=[[Online Etymological Dictionary]] |access-date=August 24, 2015}}</ref> Flatus is also the medical word for gas generated in the [[stomach]] or bowels.<ref>{{cite dictionary |url=http://www.merriam-webster.com/medlineplus/flatus |title=Medical Dictionary: Flatus |dictionary=[[Merriam-Webster]] |access-date=August 24, 2015}}</ref> Despite these standard definitions, a proportion of intestinal gas may be swallowed environmental air, and hence flatus is not totally generated in the stomach or bowels. The scientific study of this area of medicine is termed '''flatology'''.<ref name="Tangerman 2009" />

Flatus is brought to the [[rectum]] and pressurized by [[peristalsis|muscles]] in the intestines. It is normal to pass flatus, though volume and frequency vary greatly among individuals. It is also normal for intestinal gas to have a feculent odor, which may be intense. The noise commonly associated with flatulence ("[[blowing a raspberry]]") is produced by the [[external anal sphincter|anus]] and [[gluteus maximus|buttocks]], which act together in a manner similar to that of an [[embouchure]]. Both the sound and odor are sources of [[embarrassment]], annoyance or amusement ([[flatulence humor]]).

There are several general symptoms related to intestinal gas: pain, [[bloating]] and abdominal distension, excessive flatus volume, excessive flatus odor, and gas incontinence. Furthermore, [[burping|eructation]] ("an act or instance of belching", colloquially known as "burping") is sometimes included under the topic of flatulence.<ref name="K C clinical medicine">{{cite book |editor=Parveen Kumar |editor-link=Parveen Kumar |editor2=Michael L. Clark |title=Kumar & Clark Clinical Medicine |year=2005 |edition=6th |publisher=[[Saunders (imprint)|Saunders]] |location=Edinburgh |isbn=0702027634 |page=266 }}</ref> When excessive or malodorous, flatus can be a sign of a health disorder, such as [[irritable bowel syndrome]], [[celiac disease]] or [[lactose intolerance]].<ref name=NHS2017>{{cite web |title=Flatulence |url=https://www.nhs.uk/conditions/flatulence/ |publisher=NHS | date=12 December 2017}}</ref>

==Terminology==
[[File:Fart.ogg|thumb|Sound of a human flatus]]
Non-medical definitions of the term include "the uncomfortable condition of having gas in the stomach and bowels", or "a state of excessive gas in the alimentary canal". These definitions highlight that many people consider "bloating", [[abdominal distension]] or increased volume of intestinal gas, to be synonymous with the term flatulence (although this is technically inaccurate).

Colloquially, flatulence may be referred to as "farting", "pumping", "trumping",<ref>{{cite web |url=https://en.oxforddictionaries.com/definition/trump |title=trump |work=Oxford English Dictionary}}</ref> "blowing off", "pooting", "passing gas", "breaking wind", "backfiring", or simply (in [[American English]]) "gas" or ([[British English]]) "wind". Derived terms include [[vaginal flatulence]], otherwise known as a ''queef''.

==Signs and symptoms==

Generally speaking, there are four different types of complaints that relate to intestinal gas, which may present individually or in combination.

===Bloating and pain===
Patients may complain of bloating as [[abdominal distension]], discomfort and pain from "trapped wind". In the past, functional bowel disorders such as [[irritable bowel syndrome]] that produced symptoms of bloating were attributed to increased production of intestinal gas.

However, three significant pieces of evidence refute this theory. First, in normal subjects, even very high rates of gas infusion into the small intestine (30{{nbsp}}mL/min) is tolerated without complaints of pain or bloating and harmlessly passed as flatus per rectum.<ref name="Azpiroz 2005" /> Secondly, studies aiming to quantify the total volume of gas produced by patients with irritable bowel syndrome (some including gas emitted from the mouth by eructation) have consistently failed to demonstrate increased volumes compared to healthy subjects. The proportion of hydrogen produced may be increased in some patients with irritable bowel syndrome, but this does not affect the total volume.<ref name="King 1998">{{cite journal |last=King |first=TS |author2=Elia, M |author3=Hunter, JO |title=Abnormal colonic fermentation in irritable bowel syndrome |journal=[[The Lancet]] |date=October 10, 1998 |volume=352 |issue=9135 |pages=1187–9 |pmid=9777836 |doi=10.1016/S0140-6736(98)02146-1|s2cid=1750363 }}</ref> Thirdly, the volume of flatus produced by patients with irritable bowel syndrome who have pain and abdominal distension would be tolerated in normal subjects without any complaints of pain.

Patients who complain of bloating frequently can be shown to have objective increases in abdominal girth, often increased throughout the day and then resolving during [[sleep]]. The increase in girth combined with the fact that the total volume of flatus is not increased led to studies aiming to image the distribution of intestinal gas in patients with bloating. They found that gas was not distributed normally in these patients: there was segmental gas pooling and focal distension.<ref name="Azpiroz 2005" /> In conclusion, abdominal distension, pain and bloating symptoms are the result of abnormal intestinal gas dynamics rather than increased flatus production.

===Excessive volume===
The normal range of volumes of flatus in normal individuals varies hugely (476–1,491&thinsp;mL/24&thinsp;h).<ref name="Tangerman 2009" /> All intestinal gas is either swallowed environmental air, present intrinsically in foods and beverages, or the result of gut fermentation.

Swallowing small amounts of air occurs while eating and drinking. This is emitted from the mouth by eructation (burping) and is normal. Excessive swallowing of environmental air is called [[aerophagia]], and has been shown in a few case reports to be responsible for increased flatus volume. This is, however, considered a rare cause of increased flatus volume. Gases contained in food and beverages are likewise emitted largely through eructation, e.g., carbonated beverages.

Endogenously produced intestinal gases make up 74 percent of flatus in normal subjects. The volume of gas produced is partially dependent upon the composition of the intestinal microbiota, which is normally very resistant to change, but is also very different in different individuals. Some patients are predisposed to increased endogenous gas production by virtue of their gut microbiota composition.<ref name="Azpiroz 2005" /> The greatest concentration of gut bacteria is in the colon, while the small intestine is normally nearly sterile. Fermentation occurs when unabsorbed food residues arrive in the colon.

Therefore, even more than the composition of the microbiota, diet is the primary factor that dictates the volume of flatus produced.<ref name="Azpiroz 2005" /> Diets that aim to reduce the amount of undigested fermentable food residues arriving in the colon have been shown to significantly reduce the volume of flatus produced. Again, increased volume of intestinal gas will not cause bloating and pain in normal subjects. Abnormal intestinal gas dynamics will create pain, distension, and bloating, regardless of whether there is high or low total flatus volume.

===Odor===
Although flatus possesses an odor, this may be abnormally increased in some patients and cause social distress to the patient. Increased odor of flatus presents a distinct clinical issue from other complaints related to intestinal gas.<ref name="Bailey 2009">{{cite journal |last=Bailey |first=J |author2=Carter, NJ |author3=Neher, JO |title=FPIN's Clinical Inquiries: Effective management of flatulence |journal=[[American Family Physician]] |date=June 15, 2009 |volume=79 |issue=12 |pages=1098–100 |pmid=19530642}}</ref> Some patients may exhibit over-sensitivity to bad flatus odor, and in extreme forms, [[olfactory reference syndrome]] may be diagnosed. Recent informal research found a correlation between flatus odor and both loudness and humidity content.<ref>{{Cite web|last=Brain|first=Monkey|date=October 8, 2020|title=Bimodal Farts|url=https://flatology.com/bimodal-farts/|website=The Invisible College of Experimental Flatology}}</ref>

===Incontinence of flatus===
"Gas incontinence" could be defined as loss of voluntary control over the passage of flatus. It is a recognised subtype of [[faecal incontinence]], and is usually related to minor disruptions of the continence mechanisms. Some consider gas incontinence to be the first, sometimes only, symptom of faecal incontinence.<ref name="ASCRS textbook">{{citation |editor=Bruce G. Wolff |editor2=James W. Fleshman |editor3=David E. Beck |editor4=John H. Pemberton |editor5=Steven D. Wexner |title=The ASCRS textbook of colon and rectal surgery |year=2007 |publisher=[[Springer Publishing]] |location=New York |isbn=978-0-387-24846-2}}</ref>

==Cause==
Intestinal gas is composed of varying quantities of exogenous sources and endogenous sources.<ref name="NIH Gas in the">{{cite web |url=http://www.niddk.nih.gov/health-information/health-topics/digestive-diseases/gas/Pages/facts.aspx |title=Gas in the Digestive Tract |publisher=[[National Institute of Diabetes and Digestive and Kidney Diseases]] |access-date=August 24, 2015}}</ref> 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]], as is the case during [[steatorrhea]]. Anything that causes food to be incompletely digested by the [[stomach]] or [[small intestine]] may cause flatulence when the material arrives in the large intestine, due to [[Fermentation (biochemistry)|fermentation]] by [[yeast]] or [[prokaryotes]] normally or abnormally present in the [[Human gastrointestinal tract|gastrointestinal tract]].

Flatulence-producing foods are typically high in certain [[polysaccharide]]s, especially [[oligosaccharides]] such as [[inulin]]. Those foods include [[bean]]s, [[lentil]]s, [[dairy product]]s, [[onion]]s, [[garlic]], [[scallion|spring onions]], [[leek]]s, [[turnip]]s, [[rutabaga|swedes]], [[radish]]es, [[sweet potato]]es, [[potatoes]], [[cashew]]s, [[Jerusalem artichoke]]s, [[oat]]s, [[wheat]], and [[yeast]] in [[bread]]s. [[Cauliflower]], [[broccoli]], [[cabbage]], [[Brussels sprouts]] and other [[cruciferous vegetables]] that belong to the genus ''[[Brassica]]'' are commonly reputed to not only increase flatulence, but to increase the pungency of the flatus.<ref>{{Cite news|url=https://www.medicalnewstoday.com/articles/7622.php|title=Flatulence: Causes, remedies, and complications|work=Medical News Today|access-date=2018-04-17}}</ref><ref>{{Cite news|url=https://paleoleap.com/eat-brassicas-just-ones-know/|title=Paleo Foods: Brassicas (and not Just the Ones you Know) {{!}} Paleo Leap|date=2014-09-14|work=Paleo Leap {{!}} Paleo diet Recipes & Tips|access-date=2018-04-17}}</ref>

In beans, endogenous gases seem to arise from complex oligosaccharides ([[carbohydrate]]s) that are particularly resistant to digestion by mammals, but are readily digestible by [[microorganisms]] ([[methanogenesis|methane-producing]] archaea; ''[[Methanobrevibacter smithii]]'') that inhabit the [[digestive tract]]. These oligosaccharides pass through the small intestine largely unchanged, and when they reach the large intestine, [[bacteria]] ferment them, producing copious amounts of flatus.<ref name="McGee">{{cite book| last=McGee| first=Harold |author-link=Harold McGee |title=On Food and Cooking| publisher=[[Charles Scribner's Sons|Scribner]] | year=1984| isbn=0-684-84328-5| pages=257–58| title-link=On Food and Cooking }}</ref>

When excessive or malodorous, flatus can be a sign of a health disorder, such as [[irritable bowel syndrome]], [[celiac disease]], [[non-celiac gluten sensitivity]] or [[lactose intolerance]]. It can also be caused by certain medicines, such as [[ibuprofen]], [[laxative]]s, [[antifungal]] medicines or [[statin]]s.<ref name=NHS2017 /><ref name=CzajaBulsa2015>{{cite journal |author=Czaja-Bulsa G |title=Non coeliac gluten sensitivity – A new disease with gluten intolerance |journal=Clin Nutr|volume=34|issue=2|pages=189–94|date=Apr 2015|pmid=25245857 |doi=10.1016/j.clnu.2014.08.012|type=Review|doi-access=free}}</ref> Some infections, such as [[giardiasis]], are also associated with flatulence.<ref>{{cite journal|pmc=2272232 | pmid=1499664 | volume=109 | issue=1 | title=Giardia – diagnosis, clinical course and epidemiology: A review |date= 1992|jstor=3863897 | author=Flanagan PA | journal=[[Epidemiology and Infection]] | pages=1–22}}</ref>

Interest in the causes of flatulence was spurred by high-altitude [[flight]] and [[human spaceflight]]; the low [[atmospheric pressure]], confined conditions, and stresses peculiar to those endeavours were cause for concern.<ref name="McGee"/> In the field of mountaineering, the phenomenon of [[high altitude flatus expulsion]] was first recorded over two hundred years ago.

==Mechanism==

===Production, composition, and odor===
Flatus (intestinal gas) is mostly produced as a byproduct of bacterial fermentation in the gastrointestinal (GI) tract, especially the [[Colon (anatomy)|colon]].<ref name="Tomlin 1991" /> There are reports of [[aerophagia]] (excessive air swallowing) causing excessive intestinal gas, but this is considered rare.<ref name="Hemmink 2009">{{cite journal |last=Hemmink |first=GJ |author2=Weusten, BL |author3=Bredenoord, AJ |author4=Timmer, R |author5= Smout, AJ |title=Aerophagia: excessive air swallowing demonstrated by esophageal impedance monitoring |journal=[[Clinical Gastroenterology and Hepatology]] |date=October 2009 |volume=7 |issue=10 |pages=1127–29 |pmid=19602452 |doi=10.1016/j.cgh.2009.06.029}}</ref>

Over 99% of the volume of flatus is composed of odorless gases.<ref name="Tangerman 2009" /> These include oxygen, [[nitrogen]], [[carbon dioxide]], [[hydrogen]] and [[methane]]. Nitrogen is not produced in the gut, but a component of environmental air. Patients who have excessive intestinal gas that is mostly composed of nitrogen have aerophagia.<ref name="Levitt 1998" /> Hydrogen, carbon dioxide and methane are all produced in the gut and contribute 74% of the volume of flatus in normal subjects.<ref name="Suarez 1997" /> Methane and hydrogen are [[flammable]], and so [[Fart lighting|flatus can be ignited]] if it contains adequate amounts of these components.<ref name="Mercer2009">{{cite book |last=Mercer |first=Bobby |title=How Do You Light a Fart?: And 150 Other Essential Things Every Guy Should Know about Science |url=https://books.google.com/books?id=gV01_pPEO_AC&pg=PT88 |date=2009-04-18 |publisher=[[Adams Media]] |isbn=9781440519871 |page=71 |access-date=October 2, 2014}}</ref>

Not all humans produce flatus that contains methane. For example, in one study of the [[feces|faeces]] of nine adults, only five of the samples contained [[archaea]] capable of producing methane.<ref>{{cite journal| author=Miller TL|author2=Wolin MJ |author3=de Macario EC |author4=Macario AJ | title=Isolation of ''Methanobrevibacter smithii'' from human faeces| journal=[[Applied and Environmental Microbiology]] | year=1982| volume=43| pages=227–32 |pmid=6798932 |pmc=241804 |doi= 10.1128/AEM.43.1.227-232.1982| issue=1|bibcode=1982ApEnM..43..227M }}</ref> The prevalence of methane over hydrogen in human flatus may correlate with obesity, constipation and irritable bowel syndrome, as archaea that oxidise hydrogen into methane promote the metabolism's ability to absorb fatty acids from food.<ref name="Pimentel2012">{{cite journal |last=Pimentel |first=Mark |author2=Robert P Gunsalus |author3=Satish SC Rao |author4=Husen Zhang |year=2012|title=Methanogens in Human Health and Disease |journal=[[The American Journal of Gastroenterology|The American Journal of Gastroenterology Supplements]] |volume=1 |issue=1 |pages=28–33|doi=10.1038/ajgsup.2012.6 |url=http://www.nature.com/ajgsup/journal/v1/n1/full/ajgsup20126a.html}}</ref>

The remaining trace (<1% volume) compounds contribute to the odor of flatus. Historically, compounds such as [[indole]], [[skatole]], [[ammonia]] and [[short chain fatty acids]] were thought to cause the odor of flatus. More recent evidence proves that the major contribution to the odor of flatus comes from a combination of volatile [[sulfur]] compounds.<ref name="Tangerman 2009" /><ref name="Suarez 1998">{{cite journal |last=Suarez |first=FL |author2=Springfield, J |author3=Levitt, MD |title=Identification of gases responsible for the odour of human flatus and evaluation of a device purported to reduce this odour |journal=[[Gut (journal)|Gut]] |date=July 1998 |volume=43 |issue=1 |pages=100–04 |pmid=9771412 |pmc=1727181 |doi=10.1136/gut.43.1.100}}</ref> [[Hydrogen sulfide]], [[methyl mercaptan]] (also known as [[methanethiol]]), [[dimethyl sulfide]], [[dimethyl disulfide]] and [[dimethyl trisulfide]] are present in flatus. The benzopyrrole volatiles [[indole]] and [[skatole]] have an odor of mothballs, <!-- <ref name="Moore 1987" /> ref name not defined--> and therefore probably do not contribute greatly to the characteristic odor of flatus.

In one study, hydrogen sulfide concentration was shown to correlate convincingly with perceived bad odor of flatus, followed by methyl mercaptan and dimethyl sulfide.<ref name="Levitt 1998" /> This is supported by the fact that hydrogen sulfide may be the most abundant volatile sulfur compound present. These results were generated from subjects who were eating a diet high in [[pinto beans]] to stimulate flatus production.

Others report that methyl mercaptan was the greatest contributor to the odor of flatus in patients not under any specific dietary alterations.<ref name="Tangerman 2009" /><!-- <ref name="Moore 1987" /> no ref name defined --> It has now been demonstrated that methyl mercaptan, dimethyl sulfide, and hydrogen sulfide (described as decomposing vegetables, unpleasantly sweet/wild radish and rotten eggs respectively) are all present in human flatus in concentrations above their smell perception thresholds.<ref name="Tangerman 2009" />

It is recognized that increased dietary sulfur-containing amino acids significantly increases the odor of flatus. It is therefore likely that the odor of flatus is created by a combination of volatile sulfur compounds, with minimal contribution from non-sulfur volatiles.<ref name="Levitt 1998" /> This odor can also be caused by the presence of large numbers of microflora [[bacteria]] or the presence of faeces in the rectum. Diets high in protein, especially sulfur-containing amino acids, have been demonstrated to significantly increase the odor of flatus.

===Volume and intestinal gas dynamics===
Normal flatus volume is 476 to 1491 mL per 24 hours.<ref name="Tangerman 2009">{{cite journal |last=Tangerman |first=Albert |title=Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices |journal=[[Journal of Chromatography B]] |date=October 1, 2009 |volume=877 |issue=28 |pages=3366–77|doi=10.1016/j.jchromb.2009.05.026|pmid=19505855}}</ref><ref name="Tomlin 1991">{{cite journal |last=Tomlin |first=J |author2=Lowis, C |author3=Read, NW |title=Investigation of normal flatus production in healthy volunteers |journal=[[Gut (journal)|Gut]] |date=June 1991 |volume=32 |issue=6 |pages=665–669 |pmid=1648028 |pmc=1378885 |doi=10.1136/gut.32.6.665}}</ref> This variability between individuals is greatly dependent upon diet. Similarly, the number of flatus episodes per day is variable; the normal range is given as 8–20 per day.<ref name="Levitt 1998">{{cite journal |last=Levitt |first=MD |author2=Furne, J |author3=Aeolus, MR |author4= Suarez, FL |title=Evaluation of an extremely flatulent patient: case report and proposed diagnostic and therapeutic approach |journal=[[The American Journal of Gastroenterology]] |date=November 1998 |volume=93 |issue=11 |pages=2276–81 |pmid=9820415 }}</ref><!-- <ref name="Levitt 1979" /> ref name not defined--> The volume of flatus associated with each flatulence event again varies (5–375&nbsp;mL).<ref name="Tangerman 2009" /><ref name="Tomlin 1991" /><ref name="Suarez 1997">{{cite journal |last=Suarez |first=F |author2=Furne, J |author3=Springfield, J |author4= Levitt, M |title=Insights into human colonic physiology obtained from the study of flatus composition |journal=[[American Journal of Physiology]] |date=May 1997 |volume=272 |issue=5 Pt 1 |pages=G1028–33 |pmid=9176210|doi=10.1152/ajpgi.1997.272.5.G1028 }}</ref> The volume of the first flatulence upon waking in the morning is significantly larger than those during the day.<ref name="Tangerman 2009" /> This may be due to buildup of intestinal gas in the colon during sleep, the peak in peristaltic activity in the first few hours after waking or the strong prokinetic effect of rectal distension on the rate of transit of intestinal gas.<ref name="Azpiroz 2005">{{cite journal |last=Azpiroz |first=F |title=Intestinal gas dynamics: mechanisms and clinical relevance |journal=[[Gut (journal)|Gut]] |date=July 1, 2005 |volume=54 |issue=7 |pages=893–95 |doi=10.1136/gut.2004.048868|pmid=15951528 |pmc=1774596 }}</ref> It is now known that gas is moved along the gut independently of solids and liquids, and this transit is more efficient in the erect position compared to when supine.<ref name="Azpiroz 2005" /> It is thought that large volumes of intestinal gas present low resistance, and can be propelled by subtle changes in gut tone, capacitance and proximal contraction and distal relaxation. This process is thought not to affect solid and liquid intra-lumenal contents.<ref name="Azpiroz 2005" />

Researchers investigating the role of sensory nerve endings in the anal canal did not find them to be essential for retaining fluids in the anus, and instead speculate that their role may be to distinguish between flatus and faeces, thereby helping detect a need to defecate or to signal the end of defecation.<ref>{{cite journal |author=Read, M. G. |author2=Read, N. W. |title=Role of anorectal sensation in preserving continence |journal=[[Gut (journal)|Gut]] |year=1982 |volume=23 |pages=345–47 |doi=10.1136/gut.23.4.345 |pmid=7076012 |pmc=1419736|issue=4}}</ref>

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 occasionally happens accidentally, such as incidentally to [[cough]]ing or [[sneezing]] or during [[orgasm]]; on other occasions, flatulence can be voluntarily elicited by tensing the rectum or "bearing down" on stomach or bowel muscles and subsequently relaxing the anal sphincter, resulting in the expulsion of flatus.{{Citation needed|date=September 2021}}

==Management==

Since problems involving intestinal gas present as different (but sometimes combined) complaints, the management is cause-related.

===Pain and bloating===
{{Main|Abdominal distension|Bloating}}
While not affecting the production of the gases themselves, [[surfactants]] (agents that lower [[surface tension]]) can reduce the disagreeable sensations associated with flatulence, by aiding the dissolution of the gases into liquid and solid faecal matter.<ref name="brecevic">{{cite journal |vauthors=Brecević L, Bosan-Kilibarda I, Strajnar F |title=Mechanism of antifoaming action of simethicone |journal=[[Journal of Applied Toxicology]] |volume=14 |issue=3 |pages=207–11 |year=1994 |pmid=8083482 |doi=10.1002/jat.2550140311|s2cid=7453218 }}
</ref> 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.<ref name="brecevic" />

Other drugs including [[prokinetics]], [[lubiprostone]], antibiotics and probiotics are also used to treat bloating in patients with functional bowel disorders such as irritable bowel syndrome, and there is some evidence that these measures may reduce symptoms.<ref name="Schmulson 2011">{{cite journal |last=Schmulson |first=M |author2=Chang, L |title=Review article: the treatment of functional abdominal bloating and distension |journal=Alimentary Pharmacology & Therapeutics |date=May 2011 |volume=33 |issue=10 |pages=1071–86 |pmid=21488913|doi=10.1111/j.1365-2036.2011.04637.x|s2cid=20718176 |doi-access=free }}</ref>

A flexible tube, inserted into the [[rectum]], can be used to collect intestinal gas in a flatus bag. This method is occasionally needed in a hospital setting, when the patient is unable to pass gas normally.<ref>{{cite web|title=Flatus tube|url=http://www.gastrotraining.com/product-information/colorectal/flatus-tube|website=Gastro Training|access-date=3 April 2016}}</ref>

===Volume===
One method of reducing the volume of flatus produced is dietary modification, reducing the amount of fermentable carbohydrates. This is the theory behind diets such as the [[low-FODMAP diet]] (a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, alcohols, and polyols).<ref name="Staudacher 2011">{{cite journal |last=Staudacher |first=HM |author2=Whelan, K |author3=Irving, PM |author4= Lomer, MC |title=Comparison of symptom response following advice for a diet low in fermentable carbohydrates (FODMAPs) versus standard dietary advice in patients with irritable bowel syndrome |journal=Journal of Human Nutrition and Dietetics |date=October 2011 |volume=24 |issue=5 |pages=487–95 |pmid=21615553 |doi=10.1111/j.1365-277X.2011.01162.x}}</ref>

Most starches, including potatoes, corn, noodles, and wheat, produce gas as they are broken down in the large intestine.<ref name="NIH Gas in the"/> Intestinal gas can be reduced by fermenting the beans, and making them less gas-inducing, or by cooking them in the liquor from a previous batch. For example, the fermented bean product [[miso]] is less likely to produce as much intestinal gas. Some [[legume]]s also stand up to prolonged cooking, which can help break down the oligosaccharides into simple sugars. Fermentative lactic acid bacteria such as ''[[Lactobacillus casei]]'' and ''[[Lactobacillus plantarum]]'' reduce flatulence in the human intestinal tract.<ref>{{cite web |title=Study shows secret to gas-free beans |url=http://reuters.myway.com/article/20060426/2006-04-26T170153Z_01_N25328545_RTRIDST_0_ODD-BEANS-DC-DC.html |date=2006-04-26|access-date=2007-09-10 |archive-url = https://web.archive.org/web/20060502110835/http://reuters.myway.com/article/20060426/2006-04-26T170153Z_01_N25328545_RTRIDST_0_ODD-BEANS-DC-DC.html |archive-date = 2006-05-02}}</ref>

[[Probiotic]]s ([[yogurt|live yogurt]], [[kefir]], etc.) are reputed to reduce flatulence when used to restore balance to the normal [[intestinal flora]].<ref>{{cite book |last=Rubin |first=Jordan S. |author-link=Jordan S. Rubin |author2=Joseph Brasco |title=Restoring Your Digestive Health |year=2003 |publisher=[[Kensington Books]] |isbn=978-0758202826 |url-access=registration |url=https://archive.org/details/restoringyourdig00rubi }}{{page needed|date=August 2015}}</ref> Live (bioactive) yogurt contains, among other lactic bacteria, ''[[Lactobacillus acidophilus]]'', which may be useful in reducing flatulence. ''[[Lactobacillus acidophilus|L. acidophilus]]'' may make the intestinal environment more acidic, supporting a natural balance of the fermentative processes. ''[[Lactobacillus acidophilus|L. acidophilus]]'' is available in supplements. [[Prebiotics]], which generally are non-digestible oligosaccharides, such as [[fructooligosaccharide]], generally increase flatulence in a similar way as described for lactose intolerance.

[[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 |author2=Norcross WA |author3=Halverson AL |author4=Burford PA |author5=Palinkas LA | title=Does Beano prevent gas? A double-blind crossover study of oral alpha-galactosidase to treat dietary oligosaccharide intolerance| journal=The Journal of Family Practice | year=1994| volume=39| pages=441–45 |pmid=7964541| issue=5 }}</ref> The [[enzymes]] [[alpha-galactosidase]], [[lactase]], [[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]] ''[[Escherichia coli|E. coli]]'', may reduce both the production of intestinal gas and the frequency of flatus events.<ref>{{cite journal| author=Di Stefano M |author2=Strocchi A |author3=Malservisi S |author4=Veneto G |author5=Ferrieri A |author6=Corazza GR | title=Non-absorbable antibiotics for managing intestinal gas production and gas-related symptoms| journal=[[Alimentary Pharmacology & Therapeutics]] | year=2000| volume=14| pages=1001–08| doi=10.1046/j.1365-2036.2000.00808.x |pmid=10930893 | issue=8|s2cid=19613386 | doi-access=free }}</ref>

===Odor===

'''Bismuth'''

The [[odor]] created by flatulence is commonly treated with [[bismuth subgallate]], available over-the-counter in the US as Devrom. Bismuth subgallate is commonly used by individuals who have had [[ostomy]] surgery, [[bariatric surgery]], [[faecal incontinence]] and [[irritable bowel syndrome]].<ref>{{cite journal| author=Turnbull G|url=https://www.o-wm.com/content/the-issue-oral-medications-and-a-fecal-ostomy| 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 |access-date=2007-09-10}}</ref> [[Bismuth subsalicylate]] is a compound that binds hydrogen sulfide, and one study reported a dose of 524&nbsp;mg four times a day for 3–7 days bismuth subsalicylate yielded a >95% reduction in faecal hydrogen sulfide release in both humans and rats.<ref name="SuarezFurne1998">{{cite journal|last1=Suarez|first1=F.L.|last2=Furne|first2=J.K.|last3=Springfield|first3=J.R.|last4=Levitt|first4=M.D.|title=Bismuth subsalicylate markedly decreases hydrogen sulfide release in the human colon|journal=Gastroenterology|volume=114|issue=5|year=1998|pages=923–29|pmid=9558280|doi=10.1016/S0016-5085(98)81700-9}}</ref>
Another bismuth compound, bismuth subnitrate was also shown to bind to hydrogen sulfide.<ref name="Levitt 2002">{{cite journal |last=Levitt |first=MD |author2=Springfield, J |author3=Furne, J |author4=Koenig, T |author5= Suarez, FL |title=Physiology of sulfide in the rat colon: use of bismuth to assess colonic sulfide production |journal=[[Journal of Applied Physiology]] |date=April 2002 |volume=92 |issue=4 |pages=1655–60 |pmid=11896034 |doi=10.1152/japplphysiol.00907.2001}}</ref> Another study showed that bismuth acted synergistically with various antibiotics to inhibit sulfate-reducing gut bacteria and sulfide production.<ref name="Ohge 2003">{{cite journal |last=Ohge |first=H |author2=Furne, JK |author3=Springfield, J |author4=Sueda, T |author5=Madoff, RD |author6= Levitt, MD |title=The effect of antibiotics and bismuth on fecal hydrogen sulfide and sulfate-reducing bacteria in the rat |journal=[[FEMS Microbiology Letters]] |date=November 7, 2003 |volume=228 |issue=1 |pages=137–42|pmid=14612249 |doi=10.1016/s0378-1097(03)00748-1|doi-access=free }}</ref> Some authors proposed a theory that hydrogen sulfide was involved in the development of [[ulcerative colitis]] and that bismuth might be helpful in the management of this condition.<ref name="Furne 2000">{{cite journal |last=Furne |first=JK |author2=Suarez, FL |author3=Ewing, SL |author4=Springfield, J |author5= Levitt, MD |title=Binding of hydrogen sulfide by bismuth does not prevent dextran sulfate-induced colitis in rats |journal=[[Digestive Diseases and Sciences]] |date=July 2000 |volume=45 |issue=7 |pages=1439–43 |pmid=10961726|doi=10.1023/A:1005580709390 |s2cid=740767 }}</ref> However, bismuth administration in rats did not prevent them from developing ulcerative colitis despite reduced hydrogen sulfide production.<ref name="Furne 2000" /> Also, evidence suggests that colonic hydrogen sulfide is largely present in bound forms, probably sulfides of iron and other metals.<ref name="Tangerman 2009" /> Rarely, serious bismuth toxicity may occur with higher doses.<ref name="Gordon 1995">{{cite journal |last=Gordon |first=MF |author2=Abrams, RI |author3=Rubin, DB |author4=Barr, WB |author5= Correa, DD |title=Bismuth subsalicylate toxicity as a cause of prolonged encephalopathy with myoclonus |journal=[[Movement Disorders (journal)|Movement Disorders]] |date=March 1995 |volume=10 |issue=2 |pages=220–22 |pmid=7753066 |doi=10.1002/mds.870100215|s2cid=11723220 }}</ref>

''' Activated charcoal'''

Despite being an ancient treatment for various digestive complaints, [[Activated Charcoal|activated charcoal]] did not produce reduction in both the total flatus volume nor the release of sulfur-containing gasses, and there was no reduction in abdominal symptoms (after 0.52{{nbsp}}g activated charcoal four times a day for one week).<ref name="Suarez 1999">{{cite journal |last=Suarez |first=FL |author2=Furne, J |author3=Springfield, J |author4= Levitt, MD |title=Failure of activated charcoal to reduce the release of gases produced by the colonic flora |journal=[[The American Journal of Gastroenterology]] |date=January 1999 |volume=94 |issue=1 |pages=208–12 |pmid=9934757}}</ref> The authors suggested that saturation of charcoal binding sites during its passage through the gut was the reason for this. A further study concluded that activated charcoal (4{{nbsp}}g) does not influence gas formation in vitro or in vivo.<ref name="Potter 1985">{{cite journal |last=Potter |first=T |author2=Ellis, C |author3=Levitt, M |title=Activated charcoal: in vivo and in vitro studies of effect on gas formation |journal=[[Gastroenterology (journal)|Gastroenterology]] |date=March 1985 |volume=88 |issue=3 |pages=620–24 |pmid=3917957 |doi=10.1016/0016-5085(85)90129-5}}</ref> Other authors reported that activated charcoal was effective. A study in 8 dogs concluded activated charcoal (unknown oral dose) reduced hydrogen sulfide levels by 71%. In combination with yucca schidigera, and zinc acetate, this was increased to an 86% reduction in hydrogen sulfide, although flatus volume and number was unchanged.<ref name="Giffard 2001">{{cite journal |last=Giffard |first=CJ |author2=Collins, SB |author3=Stoodley, NC |author4=Butterwick, RF |author5= Batt, RM |title=Administration of charcoal, Yucca schidigera, and zinc acetate to reduce malodorous flatulence in dogs |journal=[[Journal of the American Veterinary Medical Association]] |date=March 15, 2001 |volume=218 |issue=6 |pages=892–96 |pmid=11294313 |doi=10.2460/javma.2001.218.892}}</ref> An early study reported activated charcoal (unknown oral dose) prevented a large increase in the number of flatus events and increased breath hydrogen concentrations that normally occur following a gas-producing meal.<ref name="Hall 1981">{{cite journal |last=Hall RG |first=Jr |author2=Thompson, H |author3=Strother, A |title=Effects of orally administered activated charcoal on intestinal gas |journal=[[The American Journal of Gastroenterology]] |date=March 1981 |volume=75 |issue=3 |pages=192–96 |pmid=7015846}}</ref>

'''Garments and external devices'''

In 1998, Chester "Buck" Weimer of [[Pueblo, Colorado]], received a patent for the first [[undergarment]] that contained a replaceable [[Activated carbon|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 |access-date=2007-07-27}}</ref> In 2001 Weimer received the [[Ig Nobel Prize]] for Biology for his invention.<ref>{{cite web |url=http://www.improb.com/ig/ig-pastwinners.html#ig2001 |title=The 2001 Ig Nobel Prize Winners |access-date=June 22, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110225074430/http://www.improb.com/ig/ig-pastwinners.html#ig2001 |archive-date=February 25, 2011 |df=mdy-all }}</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. |author2=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|access-date=2007-09-10}}</ref> The inventors, Myra and Brian Conant of [[Mililani, Hawaii]], still claim on their website to have discovered the undergarment product in 2002 (four years after Chester Weimer filed for a patent for his product), but state that their tests "concluded" that they should release an insert instead.<ref>{{cite web |url=http://www.flat-d.com/american-inventor.html |publisher=Flat-D Innovations Inc. |title=About the Inventor |access-date=2007-09-10}}</ref>

===Incontinence===
Flatus incontinence where there is involuntary passage of gas, is a type of [[w:faecal incontinence|faecal incontinence]], and is managed similarly.

==Society and culture==
[[File:Hegassen scroll segment 33.jpg|thumb|''[[He-gassen]]'' (detail), an art scroll depicting a battle of flatulence, from Japan during the [[Edo period]]]]
In many [[culture]]s, flatulence in public is regarded as embarrassing, but, depending on context, may also be considered humorous. People will often strain to hold in the passing of gas when in polite company, or position themselves to silence or conceal the passing of gas. In other cultures,{{Examples|date=January 2011}} it may be no more embarrassing than [[cough]]ing.

While the act of passing flatus in some cultures is generally considered to be an unfortunate occurrence in public settings, flatulence may, in casual circumstances and especially among children, be used as either a humorous supplement to a joke ("[[pull my finger]]"), or as a comic activity in and of itself. The social acceptability of flatulence-based humour in entertainment and the mass media varies over the course of time and between cultures. Enough entertainers performed with their flatus that the term [[flatulist]] was coined. The [[whoopee cushion]] is a joking device invented in the early 20th century for simulating a fart. In 2008, a farting application for the [[iPhone]] earned nearly $10,000 in one day.<ref>{{cite news |url=https://www.wired.com/gadgetlab/2008/12/iphone-fart-app/ |title=iPhone Fart App Rakes in $10,000 a Day |last=Chen |first=Brian X. |date=December 24, 2008 |work=[[Wired News]]}}</ref>

A [[fart (word)|farting]] game named ''Touch Wood'' was documented by [[John Gregory Bourke]] in the 1890s.<ref name="pennlive essay on farting">{{cite news |url=http://www.pennlive.com/midstate/index.ssf/2011/06/penn_state_professors_essay_on.html |title=Penn State professor's essay on farting takes the prize |newspaper=The Patriot-News |location=Harrisburg, Pennsylvania |date=June 8, 2011 |access-date=December 28, 2011 |author=Fishlock, Diana |quote=Trevor Blank [...] found Pennsylvania boys playing "Safety," a farting game, the same as Blank had as a kid in Maryland, and the same game John Bourke documented in the 1890s, when it was called "Touch Wood." Basically, a boy who farts must say "Safety" or touch wood before his friends say another key phrase. If not, they're allowed to punch him. (It usually is boys who make farting a game or a weapon.)}}</ref> It existed under the name of ''Safety'' in the 20th century in the U.S., and has been found being played in 2011.<ref name="pennlive essay on farting" />

In January 2011, the [[Malawi]] [[Ministry of Justice and Constitutional Affairs (Malawi)|Minister of Justice]], [[George Chaponda]], said that [[2011 Malawian Air Fouling Legislation|Air Fouling Legislation]] would make public "farting" illegal in his country. When reporting the story, the media satirised Chaponda's statement with punning headlines. Later, the minister withdrew his statement.<ref name=MaraviPost>{{cite web |url=http://maravipost.com/index.php?option=com_content&view=article&id=4663:chaponda-oops-i-goofed-you-can-fart&catid=74:general&Itemid=160#ixzz1D8VQamqG |title=Chaponda: Oops I goofed, you can fart! |date=February 4, 2011 |access-date=2011-03-02 |author=Joe Chibewa |work=Marevi Post |url-status=dead |archive-url=https://web.archive.org/web/20110714032623/http://maravipost.com/index.php?option=com_content&view=article&id=4663%3Achaponda-oops-i-goofed-you-can-fart&catid=74%3Ageneral&Itemid=160#ixzz1D8VQamqG |archive-date=July 14, 2011 |df=mdy-all }}</ref>

===Environmental impact===
[[Image:Cow female black white.jpg|thumb|The flatulence of [[cattle|cows]] is only a small portion (around one-twentieth) of cows' methane release. Cows also ''[[burp]]'' methane, due to the physiology of their digestive systems.<ref name="Distillations"/> ]]

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?"] February 3, 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. {{webarchive |url=https://web.archive.org/web/20071014025622/http://www.abc.net.au/southqld/stories/s1560903.htm?backyard |date=October 14, 2007 }}</ref> While livestock account for around 20% of global [[methane emissions]],<ref>{{cite web| url=https://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> 90–95% 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."] {{webarchive |url=https://web.archive.org/web/20040813063303/http://www.mycattle.com/health/dsp_health_article.cfm?storyid=10045 |date=August 13, 2004 }} By Gary Polakovic. ''Los Angeles Times'', July 13, 2003.</ref> In cows, gas and burps are produced by methane-generating microbes called [[methanogens]], that live inside the cow's digestive system. Proposals for reducing methane production in cows include the feeding of supplements such as [[oregano]] and [[seaweed]], and the genetic engineering of gut biome microbes to produce less methane.<ref name="Distillations">{{cite journal|last1=Kean |first1=Sam |title=Tummy Trouble |journal=Distillations |publisher=[[Science History Institute]] |date=2018|volume=4|issue=1 |page=5 |url=https://www.sciencehistory.org/distillations/magazine/tummy-trouble |access-date=June 26, 2018}}</ref>

Since [[New Zealand]] produces large amounts of agricultural products, it is in the unique position of having high methane emissions from livestock compared to other greenhouse gas sources. The New Zealand government is a signatory to the [[Kyoto Protocol]] and therefore attempts are being made to reduce [[greenhouse gas emissions|greenhouse emissions]]. To achieve this, an [[agricultural emissions research levy]] was proposed, which promptly became known as a "[[Agricultural emissions research levy|fart tax]]" or "flatulence tax". It encountered opposition from farmers, farming lobby groups and opposition politicians.

===Entertainment===
Historical comment on the ability to fart at will is observed as early as [[w:Augustine of Hippo|Saint Augustine]]'s ''[[w:City of God (book)|The City of God]]'' (5th century A.D.). Augustine mentions men who "have such command of their bowels, that they can break wind continuously at will, so as to produce the effect of singing".<ref>{{cite book |title=The City of God Against the Pagans |others=Philip Levine, editor and translator |location=Cambridge, Massachusetts |publisher=[[w:Harvard University Press|Harvard University Press]] |year=1966}}, XIV.24.</ref> Intentional passing of gas and its use as entertainment for others appear to have been somewhat well known in pre-modern Europe, according to mentions of it in medieval and later literature, including [[w:Rabelais|Rabelais]].

[[w:Le Pétomane|Le Pétomane]] ("the Fartomaniac") was a famous French performer in the 19th century who, as well as many [[w:Flatulist|professional farter]]s before him, did flatulence impressions and held shows. The performer [[w:Mr. Methane|Mr. Methane]] carries on le Pétomane's tradition today. Also, a 2002 fiction film ''[[w:Thunderpants]]'' revolves around a boy named Patrick Smash who has an ongoing flatulence problem from the time of his birth.

In literature, farting features prominently in the novel ''[[w:The Catcher in the Rye|The Catcher in the Rye]]''.<ref>{{cite book |last1=Salinger |first1=J. D. |title=The Catcher in the Rye |date=1951 |publisher=Penguin |location=London |isbn=9780140237504}}, Chapter 3</ref> Since the 1970s, farting has increasingly been featured in film, especially comedies such as ''[[w:Blazing Saddles|Blazing Saddles]]'' and ''[[w:Scooby-Doo (film)|Scooby-Doo]]''.

===Religion===
In Islam, flatulence, if audible or odorous, invalidates ''[[w:wudu|wudu]]'' (ritual purity).<ref>[http://www.sunniforum.com/forum/showthread.php?77168-Wudu-and-Passing-Wind Wudu and Passing Wind].  sunniforum.com (2011-09-03) {{webarchive |url=https://web.archive.org/web/20150515073210/http://www.sunniforum.com/forum/showthread.php?77168-Wudu-and-Passing-Wind |date=May 15, 2015 }}</ref>

==Personal experiences==
People find other peoples flatuses unpleasant, but are fine, or may even enjoy, the scent of their own flatus.<ref>{{cite web|last=Engelhaupt|first=Erika|title=People Sometimes Like Stinky Things—Here's Why|website=Nationalgeographic.com|publisher=National Geographic|date=30 September 2015|url=https://www.nationalgeographic.com/science/article/why-do-people-sometimes-like-stinky-things|access-date=3 September 2021}}</ref> There is no research on the subject matter, but some speculative guesses exist. For example, one explanation for this phenomenon is that people are very used to the scent of their own flatus, and that survival in nature may depend on the detection of and reaction to foreign scents.<ref>{{cite web|last=Millard|first=Elizabeth|title=Why You Like the Smell Of Your Own Farts|website=www.menshealth.com |publisher=Men's Health|date=10 November 2017|url=https://www.menshealth.com/health/a19542002/why-you-like-the-smell-of-your-own-farts/|access-date=3 September 2021}}</ref>

==See also==
{{col div|colwidth=30em}}
* [[w:Tympanites|Tympanites]]
* [[w:Antiflatulent|Antiflatulent]]
* [[w:Armpit fart|Armpit fart]]
* [[w:Borborygmus|Borborygmus]]
* ''[[w:The Gas We Pass|The Gas We Pass]]''
* [[w:Fart lighting|Fart lighting]]
* [[w:Eproctophilia|Eproctophilia]]
* [[w:Ralph L. Obendorf|Ralph L. Obendorf]], for the importance of flatulence-causing oligosaccharides to the seed that contains them.
{{colend}}

==References==
'''Notes'''
{{Reflist}}

'''Bibliography'''
* Allen, V. (2007) ''On Farting: Language and Laughter in the Middle Ages.'' Palgrave MacMillan. {{ISBN|978-0-312-23493-5}}.
* {{cite book |author1=Bolin, T. D. |author2= Stanton, R. |name-list-style=amp | title = Wind Breaks | publisher = Allen & Unwin | year = 1997 | isbn = 978-1-86448-321-5 }}
* {{cite book | author = Dawson, Jim | title = Who Cut the Cheese?: A Cultural History of the Fart | publisher = Ten Speed Press | year = 1999 | 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 | isbn = 1-58008-751-5 }}
* {{cite book | author = Franklin, Benjamin | editor = Japikse, Carl| title = Fart Proudly | publisher = Frog Ltd/Blue Snake | year = 2003 | edition = (Reprint) | isbn = 1-58394-079-0 | title-link = Fart Proudly}}
* Persels, J., & Ganim, R. (2004) ''Fecal Matters in Early Modern Literature and Art: Studies in Scatology''. (Chap. 1: The Honorable Art of Farting in Continental Renaissance). {{ISBN|0-7546-4116-3}}.
* {{cite book | author = von Schmausen, D. | title = Official Rules, New World Odor International Freestyle Farting Championship | publisher = LULU | isbn = 1435709195 | year = 2002}}

== External links ==
* [http://www.merck.com/mmpe/sec02/ch008/ch008d.html The Merck Manual of Diagnosis and Therapy, Gas]
* [http://www.sillyjokes.co.uk/fart-dictionary Dictionary of Fart Slang]
* [https://flatology.com/ Invisible College of Experimental Flatology]

[[Category:Flatulence| ]]
[[Category:Reflexes]]
[[Category:Digestive system]]
[[Category:Methane]]