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flatulence
Expulsion of intestinal gas per rectum.
Etiology:
1) aerophagia (swallowed air)
2) gas produced in the intestine by bacterial fermentation
a) normally gas-producing bacteria are limited to the colon
b) principal gases produced are carbon dioxide & hydrogen
c) small quantities of odiferous gases are produced
1] indoles
2] skatols
3] sulfur-containing compounds
d) substrate for bacterial fermentation
1] undigested complex carbohydrates
a] legumes - stachyose, raffinose
b] some grains: gluten
c] psyllium [2] & other insoluble fiber
d] fruits*: prunes, apricots, raisins [2]
e] vegetables: cabbage, brussels sprouts, carrots, celery, onions [2]
2] undigested fructose
3] undigested sorbitol
4] artificial sweeteners [2]
5] dairy products (lactose) [2]
3) small amounts of carbon dioxide is produced in the duodenum when HCl from the stomach or fatty acids are neutralized by bicarbonate from the pancreas
4) patients with irritable bowel syndrome often report excess flatulence & bloating [2]
5) small intestinal bacterial overgrowth is associated with excess flatulence & bloating [2]
6) carbohydrate intolerance syndromes are associated with excess flatulence
7) disorders of intestinal peristalsis are associated with excess flatulence
8) 1/3 of adults produce significant quantities of intestinal methane
a) familial trait
b) unrelated to ingestion of specific foods
* fruits less likely to cause excessive flatulence include: berries, cantaloupes, avocados, olives [2]
Pathology:
1) gas from the small intestine swallowed or internally ingested passes into the colon
2) undigested complex carbohydrates & simple sugars (fructose & sucrose) pass into the colon & provide substrate for gas-forming colonic bacteria
Clinical manifestations:
- flatulence occurs 5-15 times/day in most persons
- up to 40 times/day may be normal for some persons
Management:
1) avoidance of offending foods
a) legumes
b) some grains
c) fructose
2) Mylanta
3) chamomile
4) Iberogast ?
4) activated charcoal may be of some benefit in reducing flatulence from carbohydrate malabsorption
5) simethicone is indicated for treatment of gas retention in the GI tract
- may alter elasticity of gas bubbles
6) linaclotide may be useful for treatment of excess flatulence associated with irritable bowel syndrome with constipation (IBS-C)
Related
aerophagia
bloat
General
sign/symptom
References
- Harrison's Principles of Internal Medicine, 14th ed.
Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 234-235
- Anand BS
Fast Five Quiz: Flatulence
Medscape. Nov 1, 2022
https://reference.medscape.com/viewarticle/982818
- NIDDK Gas in the Digestive Tract
https://www.niddk.nih.gov/health-information/digestive-diseases/gas-digestive-tract