Burping

Burping (also called belching and eructation) is the release of gas from the upper digestive tract (esophagus and stomach) through the mouth. It is usually audible.

Burp
Other names	Belching, ructus, eruptus, eructation
Specialty	Gastroenterology

Causes

• Burping is usually caused by swallowing air when eating or drinking and subsequently expelling it, in which case the expelled gas is mainly a mixture of nitrogen and oxygen.[1]
• Burps can be caused by drinking beverages containing carbon dioxide, such as beer and soft drinks, in which case the expelled gas is mainly carbon dioxide.
• Diabetes drugs such as metformin[2] and exenatide[3] can cause burping, especially at higher doses. This often resolves in a few weeks.
• Burping combined with other symptoms such as dyspepsia, nausea and heartburn may be a sign of an ulcer or hiatal hernia, and should be reviewed by a physician.[4]
• Other causes of burping include: food allergy, gallbladder diseases, esophageal reflux , H. pylori, acid reflux disease[5] and gastritis.[6]

Complications

In microgravity environments, burping is frequently associated with regurgitation. With reduced gravity, the stomach contents are more likely to rise up into the esophagus when the gastroesophageal sphincter is relaxed, along with the expelled air.[7]

Disorders

• Inability to burp is uncommon
• Chest pain associated with burping can occur, but is rare.[8]

Society and culture

Acceptance

Some cultures[9] regard burping as acceptable in certain situations. In South Asia, for example, it signals the host that the guest has enjoyed the food and is full.

In Japan, burping during a meal is considered bad manners.[10] Burping during a meal is also considered unacceptable in Western cultures, such as North America and Europe.[9] In Middle Eastern countries, it is not acceptable to burp out loud in public, and one should silence one's burp, or at least attempt to do so.

Infants

An illustration depicting a woman burping an infant over her shoulder.

Babies are likely to accumulate gas in the stomach while feeding and experience considerable discomfort (and agitation) until assisted. Burping an infant involves placing the child in a position conducive to gas expulsion (for example against the adult's shoulder, with the infant's stomach resting on the adult's chest) and then lightly patting the lower back. Because burping can cause vomiting, a "burp cloth" or "burp pad" is sometimes employed on the shoulder to protect clothing.[11]

Contest

The current Guinness World Record for the loudest burp is 109.9 dB, set by UK's Paul Hunn at Butlins in Bognor Regis on 23 August 2009.[12] This is louder than a jackhammer at a distance of 1 m (3 ft 3 in).[13]

Burped speech

It is possible to voluntarily induce burping through swallowing air and then expelling it, and by manipulation of the vocal tract produce burped speech.

While this is often employed as a means of entertainment or competition, it can also act as an alternative means of vocalisation for people who have undergone a laryngectomy, with the burp replacing laryngeal phonation. This is known as esophageal speech.

Other animals

Many other mammals, such as cows, dogs and sheep also burp.

Ruminants

Much of the gas expelled is produced as a byproduct of the ruminant's digestive process. These gasses notably include a large volume of methane, produced exclusively by a narrow cohort of methanogenic archaea in the animal's gut; Escherichia coli (E. coli) and other bacteria lack the enzymes and cofactors required for methane production. A lactating cow produces about 322g of methane per day,[14] i.e. more than 117 kg per year through burping and exhalation, making commercially farmed cows a major (37%)[15] contributor to anthropogenic methane emissions, and hence to the greenhouse effect. 95% of this gas (wind) is emitted through burping.[16] This has led scientists at the Commonwealth Scientific and Industrial Research Organisation of Perth, Australia, to develop an anti-methanogen vaccine to minimize methane in cow burps.[17]

One reason why cows burp so much is that they are often fed foods that their digestive systems cannot fully process, such as corn and soy. Some farmers have reduced burping in their cows by feeding them alfalfa and flaxseed, which are closer to the grasses that they had eaten in the wild before they were domesticated.[18]

The failure to burp successfully can be fatal. This is particularly common among domesticated ruminants that are allowed to gorge themselves on spring clover or alfalfa. The condition, known as ruminal tympany, is a high-pressure buildup of gas in the stomach(s) and requires immediate treatment to expel the gas, usually the insertion of a flexible rubber hose down the esophagus, or in extreme cases the lancing of the animal's side with a trochar and cannula.

Birds

There is no documented evidence that birds burp, though ornithologists believe that there is nothing which physiologically prevents them from doing so. However, since the microbiota of birds do not include the same set of gas-producing bacteria that mammals have to aid in digestion, gas rarely builds up in the gastrointestinal tracts of birds.[19]

References

1. Cormier, René E. (1990), Walker, H. Kenneth; Hall, W. Dallas; Hurst, J. Willis (eds.), "Abdominal Gas", Clinical Methods: The History, Physical, and Laboratory Examinations (3rd ed.), Butterworths, ISBN 040990077X, PMID 21250257
2. "DailyMed: About DailyMed". Retrieved 4 October 2014.
3. "DailyMed: About DailyMed". Retrieved 4 October 2014.
4. "Eructation (Professional Guide to Signs & Symptoms (Fifth Edition)) - WrongDiagnosis.com". Better Medicine. Archived from the original on 17 July 2012. Retrieved 4 October 2014.
5. "Belching: MedlinePlus Medical Encyclopedia". medlineplus.gov. Retrieved 30 April 2020.
6. Hopman, WP; van Kouwen, MC; Smout, AJ (2010). "Does (supra)gastric belching trigger recurrent hiccups?". World Journal of Gastroenterology. 16 (14): 1795–1799. doi:10.3748/wjg.v16.i14.1795. PMC 2852831. PMID 20380015 – via PMC.
7. Vickie Kloeris (1 May 2001). Eating on the ISS Archived 30 September 2006 at the Wayback Machine. Interview with Lori Keith. National Aeronautics and Space Administration. Retrieved 2011-11-12.
8. Kahrilas, PJ; Dodds, WJ; Hogan, WJ (October 1987). "Dysfunction of the belch reflex. A cause of incapacitating chest pain". Gastroenterology. 93 (4): 818–22. doi:10.1016/0016-5085(87)90445-8. PMID 3623025.
9. Mehrotra, Shirin (10 October 2011). "To burp or not to burp". BURRP!. Archived from the original on 30 October 2013. Retrieved 30 October 2013.
10. "Dining Etiquette in Japan | articles | cultural services". Kwintessential.co.uk. Archived from the original on 29 October 2013. Retrieved 22 January 2014.
11. "Burping a Baby - Topic Overview". WebMD. 18 February 2013. Retrieved 16 April 2015.
12. "Loudest burp, male". Guinness World Records. 23 August 2009. Retrieved 3 January 2016.
13. "Decibel levels". www1.lasalle.edu. Retrieved 2 November 2018.
14. Grainger, C.; Clarke, T.; McGinn, S.M.; Auldist, M.J.; Beauchemin, K.A.; Hannah, M.C.; Waghorn, G.C.; Clark, H.; Eckard, R.J. (2007). "Methane Emissions from Dairy Cows Measured Using the Sulfur Hexafluoride (SF6) Tracer and Chamber Techniques". Journal of Dairy Science. 90 (6): 2755–2766. doi:10.3168/jds.2006-697. PMID 17517715.
15. Gerber, Pierre. "Livestock's Long Shadow" (PDF).
16. Polakovic, Gary (13 July 2003). "Bovine belching called udderly serious gas problem: Global warming concerns spur effort to cut methane". Archived from the original on 13 August 2004.
17. Nowak, R. (5 September 2004). "Burp vaccine cuts greenhouse gas emissions". New Scientist.
18. "Greening the Herds: A New Diet to Cap Gas". The New York Times. 4 June 2009.
19. Schwanke, Catherine (4 June 2009). "Is It True That Birds Can't Fart?". Popular Science. Archived from the original on 26 April 2016. Retrieved 18 June 2016.

External links

Classification	D ICD-10: R14 ICD-9-CM: 787.3 MeSH: D004884 DiseasesDB: 30089
External resources	MedlinePlus: 003080