Gas, Bloating, Belching


What Should I Know About Gas, Bloating, and Belching?

All of us at one time or another have complained about indigestion. Indigestion is a term that is used regularly, yet the symptoms it describes differ from person to person and it is up to the healthcare professional to listen to those symptoms to determine what the real problem is. Most people use the word to describe some type of upper gastrointestinal discomfort that is related to eating. Others experience stomach pain and gas. Others report intolerance to certain foods and a need to belch. All of these complaints are involved in indigestion and when they become disturbing, it is time to seek the advice of a healthcare professional.

Some people complain of chronic, repetitive belching. In most instances, each belch is preceded by a large gulp of air which passes only part of the way down the esophagus before it is expelled. Air swallowing is what generally causes excessive belching, not the production of gas in the stomach or intestine. Everyone swallows a bit of air, but some people gulp air excessively causing repeated belching. Some causes include chronic anxiety, rapid eating, drinking carbonated beverages (or any beverage through a straw), gum chewing, sucking on hard candy, smoking cigarettes, poorly fitting dentures, postnasal drip, or esophageal speech.

About 20-60 percent of intestinal gas is swallowed air. We know this because we can measure nitrogen and oxygen in the intestines and since the body does not make either of those gases, it stands to reason that the air was swallowed. (1) When swallowed air is not expelled, it passes into the stomach and intestine, giving a feeling of fullness and pressure. Upon x-ray, a large amount of air may be seen in the gastric fundus. This symptom complex is known as the gastric bubble syndrome, and may occur if the individual lies down after a meal, allowing air to become trapped by overlying fluid. This is the same condition thought to cause the "gas-bloat" syndrome observed after surgical repair of a hiatal hernia.

Many people think that the feelings of abdominal pain and bloating they experience is due to production of excessive gas. Studies have shown that these people have a normal amount of gas but may be hypersensitive to the associated pain. The average individual normally has 150 to 300ml of gas or less in the stomach and colon at any one time. (2) The amount expelled in the average person is 476 to 1,491ml daily. (3) , (4) Clues to the causes of excessive flatulence can come from analysis of the gases. Gas originates from swallowed atmospheric air, bicarbonate neutralization of stomach acids, diffusion of gases into the intestine from the blood, and bacterial fermentation. (5) The main gases produced are hydrogen and carbon dioxide. There are minute quantities of other gases and, of course, sulfur-containing compounds that give gas its characteristic odor. About one-third of the population produces methane.

Some foods, such as legumes and certain grains, increase the production of gas. These foods contain significant quantities of nonabsorbable complex carbohydrates that pass into the colon, providing an excellent place for gas-producing bacteria to grow. The most commonly studied of these foods is beans, which contain oligosaccharides that cannot be broken down in the small bowel, but pass into the colon and are metabolized by colonic bacteria. Fructose, a natural or added sweetener in fruit, fruit juices and soft drinks, and also present in oligosaccharides in, among others, broccoli, onions, asparagus, and wheat, may also be incompletely absorbed in the small intestine, and add to abdominal distention, bloating, and flatulence.

Intestinal malabsorption of sorbitol, a product used in many "sugar free" gums and candies and also used as an inert ingredient in some medications, may also cause abdominal distention, gaseousness, and bloating. Another possibility is abnormal bacterial colonization of the small intestine, inadequate digestive enzymes or infection with Guardia lamblia.


National Digestive Diseases Information Clearinghouse, National Institute of Health (NIH), Publication No. 97-883, May 1995.

    Most people produce and pass about 1 to 3 pints of gas a day and pass gas about 14 times a day.

Signs and Symptoms

[span class=alert]The following list does not insure the presence of this health condition. Please see the text and your healthcare professional for more information.[/span]

Patients’ complaints of indigestion may vary greatly, but the most frequent complaints include the feeling of “bloating”, passing gas, and belching. The feeling of pain or pressure in the stomach may also be present. Feeling full, even before a meal is done, or the feeling of being too full at the end of a normal meal is also regularly experienced. Doctors may do further testing if there is vomiting, diarrhea, fat in the stool, or the stools are very black and tarry.


  • Feeling of "bloating", waist of clothing feels tighter
  • Passing gas
  • Belching
  • Feeling of pain or pressure in the stomach (abdomen)
  • Feeling of fullness, even before a meal is done, or feeling of being too full at the end of a normal meal
  • Nausea

Treatment Options


If the cause is simply that there is too much air being swallowed, a simple explanation of how this occurs will often be sufficient and a habit recognized that can be broken. It is important to tell the healthcare professional about dietary preferences and the relationship between symptoms and eating certain foods. Often this type of assessment gives enough information to make dietary changes and relieve the complaint. Sometime, however, it is necessary to do a stool sample to check for the presence of parasites, fat, or muscle fibers. There are other tests which will determine if there is abnormal carbohydrate metabolism or an overgrowth of bacteria.

Nonprescription medications often recommended for excess gas include a product known as alpha-galactosidase, which breaks down oligosaccharides into easily digestible sugars. Another product called simethicone, is the only nonprescription antiflatulent to be approved by the FDA as safe and effective. Even though this product is referred to as something that eliminates gas, what it really does is facilitate movement so that the feeling of fullness and bloating are eliminated.

The use of activated charcoal has received some support; however the weight of evidence is not strong.

Nutritional Suplementation

Lactobacillus, Bifidobacteria

Maintaining a healthy gastrointestinal tract means having plenty of healthy bacteria such as acidophilus and bifidus. When the balance of good guys to bad guys is out of whack, it is known as dysbiosis. In one published study, patients who had developed dysbiosis from taking antibiotics were administered capsules containing 2 billion live bacteria each morning after breakfast. These patients had a relief from their symptoms within 3 to 4 days. In patients suffering from bloating, flatulence, and abdominal pain and pressure due to maldigestion, symptoms improved within one week and continued with further improvement during the second week of therapy. (6)

Herbal Suplementation


Bromelain is commonly used as an aid in digestion, being useful in minor problems such as gas and bloating to more serious ones such as gastric ulcer. Bromelain has reportedly been used successfully as a digestive in difficulties involving the pancreas and in other intestinal disorders. (7) , (8) The combination of ox bile, pancreatin, and bromelain is reportedly effective in lowering stool fat excretion in patients with a condition known as pancreatic steatorrhea, resulting in a recognizable improvement in pain, flatulence, and stool frequency. (9)

Cat's Claw

Colon toxicity has been somewhat ignored in Western medicine. It is now becoming apparent that bowel hygiene and proper flora are essential to good health. If the colon flora is out of balance (dysbiosis) or if food is not being properly digested and assimilated, toxic metabolites and mutagens may be produced. Cat’s claw is reported to have the ability to soothe irritated and inflamed tissues and help eliminate pathogens from the GI tract. (10)

Olive Leaf

As an antifungal and antiviral agent, olive leaf extract is currently used to support the maintenance of healthy bowel flora which is beneficial in problems of the digestive system. (11)

Grapefruit Seed

Grapefruit seed extract has been reported to be a broad-spectrum antimicrobial. Studies indicate that the antimicrobial activity of grapefruit seed extract causes the membrane of the invading bacteria to lose its ability to breathe and then die. (12)

Grapefruit seed extract also inhibits the growth of H. pylori and C. jejuni, both agents that cause gastrointestinal ulcers. (13)


Peppermint is a widely used herb for both medicinal and culinary purposes. Peppermint tea has long been used in treating children’s digestive problems such as colic, flatulence, and upset stomach. The oil of peppermint is used routinely in Europe as a spasmolytic, carminative, and cholagogue, with its most prevalent use in Irritable Bowel Syndrome (IBS).


Oregano oil is now used as an antifungal and antibacterial agent in various conditions. (14) A study has shown that gastrointestinal symptoms improved in seven of the 11 patients who had tested positive for Blastocystis hominis. (15)


  1. Friedman LS, Isselbacher KJ. Nausea, Vomiting, and Indigestion. In: Fauci AS, Braunwald E, Isselbacher KJ, et al, eds. Harrison’s Principles of Internal medicine, 14th ed. New York: McGraw-Hill; 1998:232-235.
  2. Altman F. Downwind update—A discourse on matters gaseous. West J Med. 1986;145:502.
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  9. Balakrishnan V, Hareendran A, Sukumaran Nair C. Double-blind cross-over trial of an enzyme preparation in pancreatic steatorrhea. J Asso Phys Ind. 1981;29:207-209.
  10. View Abstract: Sandoval-Chacon M. Antiinflammatory actions of cat's claw: the role of NF-kappaB. Aliment Pharmacol Ther. Dec1998;12(12):1279-89.
  11. View Abstract: Pugh TF, Fitch SJ. Invasive Gastric Candidiasis. Pediatr Radiol. 1986;16(1):67-8.
  12. Ionescu G, et al. Oral Citrus seed extract. J Orthomolecula Med. 1990;5(3):72-74.
  13. View Abstract: Arimi SM. Campylobacter infection in humans. East Afr Med J. Dec1989;66(12):851-5.
  14. View Abstract: Dorman HJ, et al. Antimicrobial agents from plants: antibacterial activity of plant volatile oils. J Appl Microbiol. Feb2000;88(2):308-16.
  15. View Abstract: Force M, et al. Inhibition of enteric parasites by emulsified oil of oregano in vivo. Phytother Res. May2000;14(3):213-4.