What Is Bloating, Symptoms, Causes, Treatment

What Is Bloating/Bloating is one of the most common and bothersome symptoms complained by a large proportion of patients. The term bloating refers to the subjective sensation of abdominal inflation or swelling, while visible distention refers to an actual increase in abdominal girth. This symptom has been described with various definitions, such as the sensation of a distended abdomen or an abdominal tension or even excessive gas in the abdomen, although bloating should probably be defined as the feeling (e.g. a subjective sensation) of increased pressure within the abdomen. It is usually associated with functional gastrointestinal disorders, like irritable bowel syndrome, but when bloating is not part of another functional bowel or gastrointestinal disorder it is included as an independent entity in Rome III criteria named functional bloating.

Meteorism is also known as tympanites. The primary feature of meteorism is an accumulation of gas in the gastrointestinal (GI) tract which causes a sensation of bloating and abdominal distension. One of the most common causes of flatulence is improper eating. Modification of eating habits and avoidance of certain triggers may help to alleviate symptoms.

Causes of Bloating

  • Irritable bowel syndrome – is a complex disorder of bowel motility that presents with abdominal pain and a changing pattern of bowel movements. Almost universally, patients complain of a bloated sensation. So far, no patient has shown any underlying damage to the bowel with IBS. The disorder presents with vague abdominal symptoms in the third decade of life. The disorder may be associated with diarrhea, constipation, or a combination of the two symptoms.
  • Bowel obstruction – from any cause can lead to the accumulation of gas in the intestine. This is pathological, and the patient may present with nausea, vomiting, inability to pass gas. X-rays will show dilated bowel loops, air-fluid levels, and lack of air in the distal colon or rectum.
  • Gut sensitivity – People with IBS can be extremely sensitive to gas, which can cause pain, cramping, and diarrhea.
  • Small intestinal bacterial overgrowth (SIBO) – Most healthy people have relatively few bacteria in the small intestine. People who have had intestinal surgery and/or IBS with diarrhea are more likely to have SIBO, which can cause bloating.
  • Gastroparesis – This condition causes delayed stomach emptying, which can cause bloating, nausea and even bowel blockage. Women are four times as likely as men to have gastroparesis, and as many as 40 percents of people with diabetes will also have it. Researchers are studying this condition to understand whether it may have an inflammatory or autoimmune trigger.

Common causes of abdominal bloating are

  • Overeating
  • Gastric distension
  • Lactose intolerance, fructose intolerance and other food intolerances
  • Premenstrual Syndrome
  • Food allergy
  • Aerophagia (air swallowing, a nervous habit)
  • Irritable bowel syndrome
  • Celiac disease
  • Non-celiac gluten sensitivity
  • Partial bowel obstruction
  • Gastric dumping syndrome or rapid gastric emptying
  • Gas-producing foods
  • Constipation
  • Visceral fat
  • Splenic-flexure syndrome
  • Menstruation, dysmenorrhea
  • Polycystic ovary syndrome and ovarian cysts
  • Alvarez’ syndrome, bloating of unknown or psychogenic origin without an excess of gas in the digestive tract
  • Massive infestation with intestinal parasites (e.g., Ascaris lumbricoides)
  • Diverticulosis
  • Certain medications, such as phentermine
  • This occurs in some due to salivary hypersecretion and dehydration.
  • Ovarian cancer
  • Electrolyte imbalance (hypokalemia, hypercalcemia)
  • Gastrointestinal surgery
  • Diabetes mellitus
  • Hypothyroidism
  • Use of medications like opiates
  • Spinal cord injury

Mechanical Obstruction

  • Gastric outlet obstruction
  • Small intestinal obstruction
  • Superior mesenteric artery syndrome
  • Colonic obstruction
  • Volvulus

Carbohydrate Intolerance

  • Lactase deficiency
  • Intolerance of poorly absorbed sugars (eg, fructose, sorbitol)
  • Hereditary disorders (eg, sucrase-isomaltase deficiency)
  • Intolerance of complex carbohydrates and fiber
  • Secondary causes of carbohydrate intolerance (eg, celiac disease)

Small Intestinal Bacterial Overgrowth

  • Small intestinal stasis
  • Hypochlorhydria
  • Immunodeficiency
  • Coloenteric fistula
  • Coprophagia
  • Elderly patients
  • Irritable bowel syndrome

Dysmotility Syndromes

  • Gastroparesis
  • Rapid gastric emptying
  • Gas-bloat syndrome after fundoplication
  • Chronic intestinal pseudo-obstruction
  • Slow transit constipation
  • Acute adynamic ileus
  • Acute colonic pseudo-obstruction

Functional Bowel Disorders

  • Irritable bowel syndrome
  • Functional dyspepsia
  • Functional bloating

Miscellaneous Causes

  • Aerophagia
  • Magenblase syndrome
  • Medications
  • Endocrine disorders (eg, hypothyroidism)
  • Inferior myocardial infarction

Important but uncommon causes of abdominal bloating include

  • Large intra-abdominal tumors, such as those arising from cancers of the ovarian, liver, uterus and stomach
  • Megacolon, abnormal dilation of the colon caused by some diseases, such as Chagas disease, a parasitic infection
  • Cardiopulmonary resuscitation procedures, due to the artificial mouth-to-mouth insufflation of air.

In animals, causes of abdominal bloating include

  • Gastric dilatation-volvulus, a condition of dogs which occurs when gas is trapped inside the stomach and gastric torsion prevents it from escaping
  • Ruminal tympany, a condition of ruminant animals that occurs when the gas cannot escape from the rumen.

Symptoms of Bloating

  • The most common symptom associated with bloating is a sensation that the abdomen is full or distended. Rarely, bloating may be painful or cause shortness of breath.
  • Pains that are due to bloating will feel sharp and cause the stomach to cramp.
  • Blood in your stool
  • Noticeable weight loss (without trying)
  • Vaginal bleeding (between your periods, or if you are postmenopausal)
  • Nausea
  • Vomiting
  • Diarrhea
  • Heartburn that is getting worse
  • Fever (due to an infection)

Diagnosis of Bloating

  • Blood tests – You may need blood taken to give healthcare providers information about how your body is working. The blood may be taken from your hand, arm, or IV.
  • Imaging – Small intestinal imaging is recommended by many clinicians to identify structural abnormalities that could predispose a patient to SIBO. A recent study found that the odds of having SIBO were increased 7-fold in patients with small bowel diverticula. A 4-hour solid-phase gastric-emptying scan can identify bloating patients with underlying gastroparesis.
  • Endoscopy – There is currently no role for routine endoscopy in the diagnosis of SIBO aside from sterile aspiration of the small intestine, as previously discussed. Biopsy of the duodenum may show villous blunting; however, this finding is neither sensitive nor specific for the diagnosis of SIBO.
  • Laboratory Evaluation – No serologic test is diagnostic of SIBO, although vitamin levels may provide clues as to its presence. SIBO may cause malabsorption of vitamin B12 and vitamin D; therefore, it is reasonable to check the levels of these vitamins in appropriate patients. Elevated folate levels may also point to the diagnosis of SIBO, as upper intestinal tract bacteria are capable of synthesizing folate.
  • Breath Testing – Breath testing is the most widely used diagnostic test for SIBO. Breath testing is based on the principle that bacteria produce H2 and CH4 gas in response to nonabsorbed carbohydrates in the intestinal tract; H2 gas can then freely diffuse to the bloodstream, where it is exhaled by the patient. A carbohydrate load, typically lactulose or glucose, is administered to the patient, and exhaled breath gases are analyzed at routine intervals. With lactulose, a normal response would be a sharp increase in breath H2(and/or CH4) once the carbohydrate load passes through the ileocecal valve into the colon. In a normal small intestine, glucose should be fully absorbed prior to reaching the ileocecal valve; therefore, any peak in breath H2 or CH4 is indicative of SIBO. ,

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Tests of Gut Function in Patients With Gas and Bloating

Test Category Specific Test Comments
Tests of Gut Motor Function Gastric scintigraphy Diagnoses gastroparesis or rapid gastric emptying
Octanoate breath test Alternative to scintigraphy to diagnose gastroparesis
Small intestinal/colonic scintigraphy Quantifies small intestinal/colonic transit in some academic centers
Radioopaque marker colonic transit tests A common test to diagnose slow transit constipation
Antroduodenal manometry Facilitates diagnosis of pseudoobstruction; helps distinguish neuropathic versus myopathic etiologies
Full-thickness intestinal biopsy The definitive test for pseudoobstruction; invasive
Breath Testing Lactose hydrogen breath test For lactase deficiency
Glucose hydrogen breath test Modest accuracy for diagnosis of small intestinal bacterial overgrowth
Lactulose hydrogen breath test Less accurate for diagnosis of small intestinal bacterial overgrowth; used to measure small intestinal transit; may accelerate intestinal transit
Fructose/sorbitol hydrogen breath test Uncertain diagnostic utility in patients with functional causes of bloating
Breath tests with 14C or 13C labeled substrates Require specialized facilities
Flatus Analysis Flatus quantification and gas chromatography Distinguishes aerophagia from increased gas production


Treatment of Bloating

  • Diet Eat and drink more slowly to swallow less air. Limit fatty and spicy foods. Avoid caffeine, carbonated drinks, and artificial sweeteners. Avoid common gas-causing foods, such as beans, peas, lentils, cabbage, onions, broccoli, cauliflower, and whole grains. Try removing one food at a time from your diet to see if your gas improves.
  • Fiber – Fiber has many benefits, although too much fiber may increase the amount of gas in your intestines.
  • Exercise – Regular daily exercise often reduces symptoms in the stomach and intestines.
  • Laxatives – Over-the-counter laxatives, such as polyethylene glycol may help with constipation but probably not with stomach pain.

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Medical Therapies for Gas and Bloating

Medication Class Examples Comments
Enzyme Preparations β-galactosidase (lactase) For lactose intolerance; variable effectiveness in lactose intolerant IBS patients
α-galactosidase Effective for legume-rich meals
Pancreatic enzymes Uncertain efficacy for gas and bloating
Sacrosidase May help in sucrase-isomaltase deficiency
Adsorbents and Agents That Reduce Surface Simethicone Possible benefits in functional dyspepsia and gas with diarrhea
Activated charcoal Possible benefits in gas production and malodorous flatus; charcoal-lined undergarments are available
Bismuth subsalicylate Possible benefits in reducing malodorous flatus
Treatments to Modify Gut Flora Antibiotics Useful for bacterial overgrowth; uncertain benefits in IBS
Probiotics (Lactobacillussp., Bifidobacterium sp.) Possible benefits in IBS
Prebiotics Uncertain benefits
Prokinetic Medications Tegaserod Reduces bloating in IBS
Neostigmine Reduces luminal distention in acute colonic pseudoobstruction; uncertain benefits in bloating
Octreotide Reduces symptoms in pseudoobstruction with bacterial overgrowth alone or combined with erythromycin




Probiotics are defined as live microorganisms that confer a health benefit on the host when administered in adequate amounts. Although probiotics are commonly used, most have not been adequately evaluated in randomized, placebo-controlled trials. A recent prospective study of the probiotics Lactobacillus acidophilus and Bifidobacterium lactis in patients with unconstipated functional bowel disorders found an improvement in bloating severity during an 8-week trial period.


Antibiotics a gut selective antibiotic that is not systemically absorbed is one of the best-studied antibiotics for the treatment of bloating. In a double-blind, randomized, placebo-controlled trial, 81 patients with IBS (based on Rome I criteria) were assigned to receive either rifaximin (400 mg 3 times daily) or placebo for 10 days. Patients who received rifaximin reported improvement in global IBS symptoms as well as bloating symptoms compared to patients who received a placebo.

Treatment Details

  • Also, combinations of prokinetics – such as domperidone + metoclopramide + diphenhydramine (the latter for the prevention of extrapyramidal reactions, especially acute dystonic reactions) + proton pump inhibitors (PPIs), have dramatic effects on bloaters and belchers especially.
  • Antidiarrheal medicines  Over-the-counter loperamide may help with diarrhea but probably not with stomach pain.
  • Tricyclic Antidepressants – Tricyclic antidepressants (TCAs) are frequently used to treat functional abdominal pain. Data from a randomized, controlled trial comparing desipramine with cognitive behavioral therapy demonstrated an improvement in patients with functional abdominal pain as well as an improvement in bloating. An ongoing research study (the National Institute of Health’s Functional Dyspepsia Treatment Trial) may provide further information on the efficacy of TCAs for the treatment of bloating associated with FD.
  • Smooth Muscle Antispasmodics – Smooth muscle antispasmodics are routinely used by clinicians to treat abdominal pain that is associated with IBS. Although several trials in Europe have shown an improvement in symptoms in patients treated with these drugs, data from clinical trials in the United States are limited, and these medications (eg, mebeverine, polonium, and trimebutine) are not available in the United States.
  • Osmotic Laxatives These agents, the most common of which is polyethylene glycol, improve symptoms of constipation. One prospective study found that symptoms of bloating improved when patients with chronic constipation were treated with a polyethylene glycol solution. These agents have not been studied in patients who complain predominantly of bloating.
  • Neostigmine – is a potent cholinesterase inhibitor that is used in the hospital setting to treat acute colonic pseudo-obstruction. In a prospective study of 28 patients with abdominal bloating who underwent jejunal gas infusion, intravenous neostigmine induced significant and immediate clearance of retained gas compared to placebo.
  • Cisapride –  is a mixed 5-HT3/5-HT2 antagonist and 5-HT4 agonist that was previously used to treat reflux, dyspepsia, gastroparesis, constipation, and IBS symptoms. The drug was withdrawn from the US market in July 2000. In a study of FD patients, cisapride improved symptoms of bloating in some patients, although the benefits were not overwhelming. Cisapride did not improve bloating in patients with IBS and constipation.
  • Domperidone – Domperidone is a dopamine antagonist used to treat FD, gastroparesis, and chronic nausea. Although this drug may improve dyspeptic symptoms (including upper abdominal bloating) in some patients, its routine use in clinical practice is precluded by the absence of prospective, randomized, controlled studies evaluating its efficacy in patients with functional bloating.
  • Metoclopramide Metoclopramide is a dopamine antagonist approved for the treatment of diabetic gastroparesis. Patients with FD and gastroparesis frequently have symptoms of bloating. One small study found that metoclopramide did not improve symptoms of abdominal distention in dyspeptic patients.
  • Tegaserod  – Tegaserod is a 5-HT4 (serotonin type 4) receptor agonist that stimulates GI peristalsis, increases intestinal fluid secretion, and reduces visceral sensation. In July 2002, this drug was approved by the US Food and Drug Administration for the treatment of IBS with constipation in women, as studies showed an improvement in bloating symptoms with the drug. Although tegaserod has since been withdrawn from the US market, it is still available for emergency use. Other 5-HT4 agonists (ie, prucalopride) may become available in the United States in the future
  • Linaclotide – Linaclotide, a minimally absorbed peptide that is an agonist of guanylate cyclase-C, has shown promising efficacy in IBS-C and chronic constipation. It increases fluid secretion and accelerates intestinal transit by activating the cystic fibrosis transmembrane conduction regulator. In addition, at higher doses in animal models, it has been shown to result in a reduction in visceral hypersensitivity via the direct inhibition of colonic nociceptors.,
  • Lubiprostone – Lubiprostone, a member of the pro stone class of compounds, also acts on chloride channels to relieve constipation and improve colonic transit. Most studies use the primary endpoint of increased frequency of spontaneous bowel motions, with decreases in abdominal pain and bloating as secondary endpoints. Once again, there appears to be a significant decrease in abdominal bloating.
  • 5-Hydroxytryptamine Agonists – Prucalopride and tegaserod, which are 5-hydroxytryptamine receptor 4 (5-HT4) agonists, stimulate gastrointestinal motility and intestinal secretion. Tegaserod has been withdrawn from the market because of the risk for serious cardiac side effects. Prucalopride is a highly selective 5-HT4 agonist with few serious adverse events.
  • Smooth Muscle Antispasmodics Smooth muscle antispasmodics are routinely used by clinicians to treat abdominal pain that is associated with IBS. Although several trials in Europe have shown an improvement in symptoms in patients treated with these drugs, data from clinical trials in the United States are limited, and these medications (eg, mebeverine, polonium, and trimebutine) are not available in the United States. Because these medications relax smooth muscle, they have the potential to cause further gas accumulation within the GI tract and to delay transit of gas through the GI tract. Thus, although these agents are commonly used to treat cramps and spasms within the GI tract, they have the potential to worsen symptoms of gas and bloating; therefore, they cannot be recommended for routine use.
  • Osmotic Laxatives These agents, the most common of which is polyethylene glycol, improve symptoms of constipation. One prospective study found that symptoms of bloating improved when patients with chronic constipation were treated with a polyethylene glycol solution. These agents have not been studied in patients who complain predominantly of bloating.
  • Experts suggest – that one should avoid overeating. Limit food intake to 4 to 7 small meals a day rather than 3 large meals. Next, avoid foods that are rich in fat and simple carbohydrates. Fats take a lot longer to digest, and since they remain in the abdomen a lot longer, the symptoms of bloating may continue for many hours. The low FODMAP diet has been shown to reduce bloating sensation in individuals.
  • Avoid eating too fast as one may swallow air. Eating slowly is the key and also suppresses the desire to eat more. Foods should be chewed thoroughly.
  • Drinking beverages while eating food or immediately after should be avoided as this will promote flatulence in some people. Beverages, vegetables, and fruits should be consumed at least 1 hour after food.
  • Adding ginger, cumin and some herbs such as dill, parsley, basil are beneficial to remove flatulence.

Home Remedies For Bloating and Gas Relief

The best way to relieve and even prevent symptoms of stomach bloating and gas is a healthy diet and regular exercise, however, there are many things you can do to prevent and relieve bloating and gas.

  • Identify foods that cause you to have bloating or gas, and eliminate them from your diet. Other than vegetables and fruits, many of these foods are not necessary for a healthy and balanced diet.
  • Stay active and exercise to help your digestive system function at its best.
  • Don’t smoke cigarettes because it can cause or aggravate bloating and gas.
  • Eat smaller portions if you feel bloated after overeating.
  • Reduce your intake of fatty foods, which can contribute to feeling overly full.
  • Eat more slowly. It can take up to 20 minutes to feel full after you’ve started eating.
  • To reduce excess swallowed air that can cause gas and bloating, avoid carbonated beverages such as sodas, drinking with straws, and chewing gum.
  • When adding high fiber foods to the diet, do so gradually to allow the body time to adjust.
  • Reduce salt intake
  • Don’t smoke as this can cause or aggravate bloating and gas.
  • Take a walk after eating to stimulate digestion.

You can try natural remedies to relieve bloating and gas.

  • Peppermint tea
  • Ginger
  • Chamomile tea
  • Pumpkin

Talk with your doctor or other health care professional before using any natural or home remedies because they may have unwanted side effects or interactions with medications you currently take.


To decrease the gassiness, the following is recommended

  • Do not drink fluids through a straw
  • Avoid consuming carbonated sodas
  • Do not suck on candy
  • Psychotherapy has also been found to improve the quality of life in patients with functional dyspepsia.
  • Avoid the foods that are known to cause gas. These include cabbage, Brussels sprouts, turnips, beans, and lentils.
  • Avoid chewing gum.
  • Avoid using straws for drinking.
  • Reduce or avoid drinking carbonated drinks (such as soda).
  • Reduce or avoid eating and drinking foods and drinks that include fructose or sorbitol. These artificial sweeteners are often found in sugar-free foods.
  • Slow down when you eat.
  • Eat more foods high in fiber to prevent constipation. If foods alone don’t help, consider taking a fiber supplement.
  • Avoid dairy products if you notice they cause gas and bloating.

Avoid the following foods

There are certain foods that can worsen bloating and cause gassiness. These include the following:

  • Research has shown that low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet can reduce the symptoms of gas and IBS. A low FODMAP diet avoids fermentable, gas-producing food ingredients, such as:
    • Oligosaccharides, which are found in wheat, onions, garlic, legumes and beans
    • Disaccharides, such as lactose in milk, yogurt and ice cream
    • Monosaccharides, including fructose (a type of sugar found in honey), apples and pears
    • Polyols or sugar alcohols found in foods such as apricots, nectarines, plums and cauliflower, as well as many chewing gums and candies
  • Lentils and beans contain indigestible sugars which are broken down by bacteria, resulting in the generation of gas
  • Fruits and vegetables like carrots, cabbage, Brussel sprouts,  prunes, and apricots also cause gassiness
  • Artificial sweeteners like sorbitol are not easy to digest and hence are broken down by bacteria to produce gas.
  • Patients with meteorism should avoid dairy products as they can worsen the bloating sensation.
  • Wheat contains a protein called gluten which may cause bloating. Gluten should be included in the elimination diet to rule out gluten sensitivity.
  • Finally, people prone to meteorism should become physically active as this can also lead to increased peristalsis and emptying of gas from the intestine.


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What Is Bloating

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