Gas and StephenGas E. Goldfinger,and Bloating MD; J. Thomas LaMont, MD; Leah K. Moynihan, RNC, MSN; Peter A. L. Bonis, MD. Stephen E. Goldfinger, MD; J. Thomas LaMont, MD; Leah K. Moynihan, RNC, MSN; Peter A. L. Bonis, MD.

Gas and Bloating Some people feel that they pass too much gas (fatulence) or burp too frequently, both of which can be Gas and Bloating Some people feel that they pass too much gas (fatulence) or burp too frequently, both of which can be a source of embarrassment and discomfort. The average adult produces about one to three pints of gas each day, which is a source of embarrassment and discomfort. The average adult produces about one to three pints of gas each day, which is passed through the anus 14 to 23 times per day. occasionally before or after meals is also normal. passed through the anus 14 to 23 times per day. Burping occasionally before or after meals is also normal. The amount of of gas gas produced produced by by the the body body depends depends upon upon a person’s a person’s diet anddiet individualand individual factors. factors. However, However, most people most people who complain of of excessive excessive gas gas do do not not produce produce more more gas gasthan than the averagethe average person. person. Instead, Instead, they often they have often an have increased an increased awareness ofof normal normal amounts amounts of ofgas. gas. On the otherother hand, hand, several several foods foods and and medical medical conditions conditions can cancause cause excessive excessive gas production. gas production. This topic This reviews topic reviews the the sources ofof intestinalintestinal gas, gas, conditions conditions that that increase increase sensitivity sensitivity to gas, to gas,and measuresand measures to reduce to reduce gas production. gas production.

Source ofof GasGas intestine. However, certain carbohydrates are incompletely There are two primary sources of intestinal gas: gas that is intestine. However, certain carbohydrates are incompletely There are two primary sources of intestinal gas: gas that is digested, allowing bacteria in the colon to digest them. The ingested (mostly swallowed air) and gas that is produced by digested, allowing bacteria in the colon to digest them. The ingested (mostly swallowed air) and gas that is produced by by-products of bacterial digestion include odorless vapors, bacteria in the colon. by-products of bacterial digestion include odorless vapors, bacteria in the colon. such as carbon dioxide, hydrogen, and methane. Minor such as carbon dioxide, hydrogen, and methane. Minor Air swallowing components of fatus (gas expelled through the anus) have Air swallowing an unpleasantcomponents odor, of including fatus (gas trace expelled amounts through of sulfur- the anus) have Air swallowing is the major source of gas in the . It containingan unpleasant gases that odor, are released including by tracebacteria amounts in the large of sulfur- Airis normal swallowing to swallow is the a majorsmall amountsource of airgas when in the eating stomach. and It intestine.containing gases that are released by bacteria in the large is normal to swallow a small amount of air when eating and drinking and when swallowing saliva. Larger amounts of air intestine. drinkingmay be swallowed and when when swallowing eating food saliva. rapidly, Larger gulping amounts liquids, of air Some carbohydrates, such as raffnose, are not well maychewing be swallowed gum, or smoking. when eating food rapidly, gulping liquids, digested,Some and carbohydrates, therefore cause such increased as raffnose, amounts are of not gas. well A numberdigested, of vegetables and therefore contain causeraffnose, increased such as amountscabbage, of gas. A chewingMost swallowed gum, or air smoking. is eliminated by belching (or “eructation”), Brussels sprouts, asparagus, broccoli, and some whole so that only a relatively small amount passes from the stomach number of vegetables contain raffnose, such as cabbage, Most swallowed air is eliminated by belching (or “eructation”), grains. As a result, these foods tend to cause more gas and into the small intestine. However, posture may infuence how Brussels sprouts, asparagus, broccoli, and some whole so that only a relatively small amount passes from the stomach fatulence. much air passes to the small intestine. In an upright position, grains. As a result, these foods tend to cause more gas and into the small intestine. However, posture may infuence how most swallowed air passes back up the and is Somefatulence. people are not able to digest certain carbohydrates. much air passes to the small intestine. In an upright position, A classic example is lactose, the major sugar contained in expelled through the mouth. On the other hand, when lying Some people are not able to digest certain carbohydrates. mostdown, swallowed swallowed airair passestends to back pass upinto the the esophagus small intestine. and is dairy products. Thus, consuming large amounts of lactose A classic example is lactose, the major sugar contained in expelledSome of the through oxygen the and mouth. nitrogen On in the swallowed other hand, air may when be lying may lead to increased gas production, along with cramping dairy products. Thus, consuming large amounts of lactose down,absorbed swallowed through the air walls tends of to the pass GI tractinto theinto smallthe bloodstream. intestine. and . Some of the oxygen and nitrogen in swallowed air may be may lead to increased gas production, along with cramping Belching may be voluntary or occur unintentionally. Certain diseases can also cause excessive bloating and absorbed through the walls of the GI tract into the bloodstream. and diarrhea. Involuntary belching is a normal process that typically occurs gas. For example, people with diabetes or scleroderma Belchingafter eating may to release be voluntary air that orenlarges occur orunintentionally. stretches the stomach. may, Certainover time, diseases have slowing can also in causethe peristaltic excessive (forward bloating and InvoluntaryBelching is more belching common is a normalwith certain process foods that that typically relax the occurs propulsion)gas. For activity example, of the people small withintestine. diabetes This can or scleroderma lead to bacterial overgrowth within the bowel, with poor digestion afterring-shaped eating tomuscle release (sphincter) air that aroundenlarges the or lower stretches end ofthe the stomach. may, over time, have slowing in the peristaltic (forward of carbohydrates and other nutrients. Belchingesophagus is where more itcommon joins the withstomach. certain Such foods foods that include relax the propulsion) activity of the small intestine. This can lead to peppermint, chocolate, and fats. bacterial overgrowth within the bowel, with poor digestion ring-shaped muscle (sphincter) around the lower end of the Gas and Bloating Symptoms esophagus where it joins the stomach. Such foods include of carbohydrates and other nutrients. Bacterial production Some people feel they pass an excessive amount of gas peppermint, chocolate, and fats. The colon normally provides a home for billions of harmless from Gasbelow and or burp Bloating too frequently Symptoms. Other people notice Bacterialbacteria, some production of which support the health of the bowel. and crampy . Such Carbohydrates are normally digested by enzymes in the small pain Somemay be people perceived feel inthey areas pass where an excessive gas can become amount of gas The colon normally provides a home for billions of harmless from below or burp too frequently. Other people notice bacteria, some of which support the health of the bowel. abdominal distension and crampy abdominal pain. Such Carbohydrates are normally digested by enzymes in the small pain may be perceived in areas where gas can become GASTROENTEROLOGY CONSULTANTS OF SAN ANTONIO GASBLO-10/09 PAGE 1

GASTROENTEROLOGY CONSULTANTS OF SAN ANTONIO GASBLO-10/09 PAGE 1

Gas and Bloating trapped, such as in bends in the colon, which occur naturally the United States, lactose intolerance affects 7 to 20 percent of in the area under the (upper to mid right part of the people who are white, 80 to 95 percent of Native Americans, ), and in the area under the spleen (upper to mid left 65 to 75 percent of Africans and African Americans, and 50 part of the abdomen). percent of Hispanics. More than 90 percent of people in some regions of eastern Asia have lactose intolerance. Sensitivity To Gas Lactose intolerance is caused by an impaired ability to digest The link between fatulence, belching, and the actual amount lactose, the principle sugar in dairy products. Symptoms of of gas in the intestines is not always clear. The vast majority of lactose intolerance include diarrhea, abdominal pain, and people who complain about gas-related symptoms do not have fatulence after consuming milk or milk-containing products. an excessive amount of gas in the intestine, but rather they People who avoid dairy products should take a supplement have an increased sensitivity to normal amounts of gas in the that contains 1000 mg of calcium and 400 IU vitamin D intestine. This can happen in a variety of circumstances. since dairy products are a primary source of these important Irritable bowel syndrome substances. This is especially true for children and women. Many people with irritable bowel syndrome (IBS) are sensitive Intolerance to other sugars — In addition to lactose and to normal amounts of gas. Nerves that carry sensory messages raffnose, some people are intolerant of other sugars contained from the bowel may be overactive in people with IBS, so that in foods. Two common examples are fructose (contained in normal amounts of gas or movement in the gastrointestinal tract dried fruit, honey, sucrose, onions, artichokes, and many foods are perceived as excessive and painful. The primary symptoms and drinks that contain “high fructose corn syrup”) and sorbitol of IBS are abdominal pain and altered bowel habits. Many (a sugar substitute contained in some sugar free candies and people also complain of abdominal distension. chewing gum). Some people with severe IBS feel better when treated with Diseases associated with increased gas medications that decrease the perception of painful sensations • Bacterial overgrowth coming from the intestine (such as low doses of imipramine or nortriptyline). • Celiac disease (a disease caused by intolerance to a protein contained in wheat), short bowel syndrome Causes of Increased Gas Gas and Bloating Diagnosis The vast majority of people with gas-related complaints do not produce excessive amounts of gas. However, there are several The need for diagnostic tests depends upon the individual’s conditions that may lead to increased gas formation. situation. Aerophagia — Chronic, repeated belching usually occurs Specifc tests may include: when a person frequently swallows large amounts of air (i.e., • Examination of stool to detect the presence of blood, aerophagia). Aerophagia is typically an unconscious process. abnormally increased levels of fat (steatorrhea), or the Treatment focuses on decreasing air swallowing by eating presence of a parasite (Giardia). slowly without gulping and avoiding carbonated beverages, • A lactose tolerance test. chewing gum, and smoking. • X-ray examination of the small intestine. Foods that cause gas — Several foods contain the carbohydrate raffnose, which is poorly digested and increases gas • A procedure to examine the inside of the stomach and/or production. Foods that contain raffnose include beans, colon (upper endoscopy, sigmoidoscopy, or colonoscopy) cabbage, caulifower, Brussels sprouts, broccoli, and asparagus. may be recommended. Avoiding these foods or eating them infrequently may reduce • Antibody tests for celiac disease. gas production. Starch and soluble fber can also contribute to gas formation. Gas and Bloating Treatment Potatoes, corn, noodles, and wheat produce gas while rice does Diet recommendations not. Soluble fber (found in oat bran, peas and other legumes, beans, and most fruit) also causes gas. Some laxatives contain Avoid foods that appear to aggravate symptoms. These may soluble fber and may cause gas, particularly during the frst few include milk and dairy products, certain fruits or vegetables, weeks of use. whole grains, artifcial sweeteners, and/or carbonated beverages. A record of foods and beverages consumed over Lactose intolerance — Intolerance to lactose-containing foods time may help to pinpoint which foods are bothersome. (primarily dairy products) is a common problem. In Europe and

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Gas and Bloating

If you are lactose intolerant, do not consume products that contain lactose and use a lactose-digestive aid, such as lactose- reduced milk or over-the-counter lactase supplements (e.g., LactAid® tablets or liquid). People who avoid dairy products should take a calcium supplement.

Over-the-counter medications Try an over-the-counter product that contains simethicone, such as certain antacids (eg, Maalox® Anti-Gas, Mylanta® Gas, Gas-X®, Phazyme®). Simethicone causes gas bubbles to break up and is widely used to relieve gas, although its beneft is questionable. Try an over-the-counter product that contains activated charcoal (eg, Charcocaps®, CharcoAid®). Evidence concerning the beneft of activated charcoal is contradictory: its beneft has been supported by some studies and refuted by others. It is reasonable to try. Try Beano™, an over-the-counter preparation that contains an enzyme (alpha-galactosidase), which helps to breakdown certain complex carbohydrates. This agent may be effective in reducing gas production and frequency in people who have increased gas after eating beans or other vegetables that contain raffnose. Try bismuth subsalicylate (eg, Pepto-Bismol®) to reduce the odor of unpleasant smelling gas due to hydrogen sulfde, a sulfur-containing compound.

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