Belching, Bloating, and Flatulence

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Belching, Bloating, and Flatulence Overview

• What is intestinal gas and when do people have symptoms?

  It is normal for our gastrointestinal tract to have gas. Some gas is swallowed and some gas is made within the gut as part of the digestion process. Certain medical conditions can cause increased gas within the intestines, but people can also be sensitive to normal amounts of gas and experience symptoms even when the amount of gas in the intestinal tract is not significantly increased. Nearly everyone has experienced the sensation of bloating, or increased “gassiness”, on occasion, but for some people, bloating occurs frequently and can negatively affect quality of life. Commonly reported symptoms of gassiness are belching, bloating, distension, and flatulence. Often these symptoms are not particularly harmful and rarely signify a major underlying medical problem.

Symptoms

• What are the symptoms of belching, bloating, distension and flatulence?

  Belching is a noisy, sometimes forceful expulsion of air from the stomach through the mouth. This is often a normal process after eating, and generally painless. However, if belching occurs too frequently or is noisy, people can perceive this as socially disturbing and bothersome.
  Bloating is a subjective sensation of trapped gas or inflation within the abdomen which is uncomfortable. Bloating can be experienced with or without abdominal distension.
  Distension is an objective increase in abdominal girth, which can be experienced with or without the sensation of bloating, though these symptoms frequently occur together.
  Flatulence is the passage of air or gas via the anus. Though not painful, people can perceive the sound of flatulence or release of foul-smelling gas as embarrassing.

• If I have gas-related symptoms, is it possible for testing to be normal?

  Yes. Symptoms can occur without any physical abnormality within the intestinal tract. Often, symptoms may be more noticeable during periods of increased stress or during normal hormone related changes, such as menstruation in women. Social, cultural, psychological, medication and dietary factors may also contribute to symptoms. Therefore, while symptoms may be bothersome, they do not necessarily signify a problem with the intestinal tract.

Causes

• What causes ‘gas’-related symptoms?

  Gas-related symptoms can be attributed to several disorders of the gastrointestinal tract. Importantly, individuals with seemingly similar gas-related symptoms (i.e. bloating) can have different underlying problems. Symptoms can originate from the stomach, the small intestine, or the colon.

  Excess air can be swallowed when eating hastily or while chewing gum or drinking from a straw. Drinking carbonated beverages may contribute as well. People who use a CPAP machine for sleep apnea may feel the sensation of trapped abdominal air in the morning. Sometimes stress or anxiety can increase the act of swallowing air, and a person may be unaware of this. Further, some people may subconsciously learn a habit of belching to try to relieve symptoms of bloating.

  Bloating after meals, which is associated with abdominal pain or fullness may be related to a common disorder of gut-brain interaction called “functional dyspepsia”. In this case, the symptoms of bloating and abdominal discomfort are thought to be due to overly sensitive nerves within the gastrointestinal tract and a general disconnect in the communication between the gut and the brain – hence the name “disorder of gut-brain interaction”. Bloating can also occur as a side effect of several medications, including popular weight loss medications called GLP-1 agonists which can slow the emptying of the stomach.

  Additionally, people can experience bloating, abdominal cramping, and flatulence when they ingest milk, certain cheeses or ice cream because they lack the enzyme (lactase) which is required to digest milk sugars (lactose). This condition, called lactose intolerance, is less common in people of northern European origin. Other people can experience similar symptoms with ingestion of fructose (a sugar found in many fruits, vegetables and honey) or gluten (a protein found in wheat, barley and rye). Celiac disease is a well-known disorder of the immune system which is triggered by eating gluten, but celiac disease is uncommon and some people without true celiac disease can be sensitive to gluten (so-called “non-celiac gluten sensitivity”). Additionally, foods high in fiber, such as beans, and “cruciferous vegetables”, such as cabbage, cauliflower, and broccoli can cause some people to experience bloating or excess flatulence.

  Slow movement of the gastrointestinal tract can cause bloating. Poorly controlled diabetes can affect the movement of intestinal tract, particularly the stomach (slow movement of the stomach is called “gastroparesis”), which can lead to bloating. Constipation, or delayed emptying of colon, can cause bloating. This can occur for a variety of reasons, including as a side effect of medications. A frequently unrecognized cause of constipation is “pelvic floor dysfunction”, which is more common in women. This occurs due to incomplete relaxation of muscles in the pelvis and anal canal, thereby making it difficult to have a complete and effective bowel movement. People with pelvic floor dysfunction can report bloating due to difficulty passing gas or stool. Constipation can also occur in another common disorder of gut-brain interaction called “irritable bowel syndrome, or (IBS)”, and patients with IBS frequently report bloating.

  Overgrowth of intestinal bacteria (“small intestinal bacterial overgrowth”, or “SIBO”) can cause bloating and distension in some people, though the true prevalence of SIBO is unknown. This is not an infection with harmful bacteria but an overgrowth of normal intestinal bacteria.

Risk Factors

• What are the risk factors for belching, bloating, distension and flatulence?

  As mentioned above, excessive air swallowing, certain foods, carbonated beverages, some medications, and even stress can contribute these symptoms. Patients with disorders of gut-brain interaction, such as irritable bowel syndrome and functional dyspepsia are uniquely sensitive to normal or only slightly increased volumes of intestinal gas and may develop symptoms of abdominal bloating and distension as a result. Constipation is another common risk factor for bloating and distension, and this can occur as a result of medications, other medical problems (i.e. diabetes, Parkinson’s disease), slow movement of the colon, in the setting of IBS, and even pelvic floor dysfunction as highlighted above. Patients with altered anatomy due to surgery (such as a gastric bypass) or those with certain connective tissue disorders (such as scleroderma) may be at an increased risk of excess bacterial overgrowth in the small intestine (SIBO) which can lead to gas-related symptoms.

Diagnosis

• How are gas-related problems diagnosed?
  Currently, there is no standard set of tests that must be completed for every individual with gas-related symptoms. Therefore, the tests used to make a diagnosis are highly individualized and dependent on the individual’s age, medical and surgical history, as well as the nature and severity of his/her symptoms. When symptoms become recurrent and bothersome, it may be appropriate to seek medical care. In the initial evaluation, a review of one’s diet and medications can be a good first step. Sometimes imaging of the abdomen is helpful and this can be done with a simple X-ray or a more detailed CT scan or MRI (to look for evidence of increased gas or stool within the intestinal tract, the presence of inflammation within the abdomen/pelvis, or a structural abnormality or mass). An upper endoscopy (examining the esophagus and stomach with a flexible camera scope while one is sedated) can be helpful in some cases to assess for inflammation within the esophagus, stomach, or first part of the small intestine. Tissue biopsies can be obtained during an upper endoscopy to assess for celiac disease; however, testing for celiac disease can also be done with blood tests. Further, “breath tests” can be done to test for lactose intolerance, fructose intolerance, as well as small intestinal bacterial overgrowth. These tests involve measuring the levels of certain gases (i.e. hydrogen, methane) in one’s breath at different times (often over the course of 2 hours), following ingestion of a specific sugar. Finally, less commonly, several specialized tests, such as tests evaluating the motility (movement) of the gastrointestinal tract or assessing for pelvic floor dysfunction, can be considered, though these are needed less commonly.

Treatment

• How is belching, bloating, bloating and flatulence treated?

  As with testing, treatment of gas-related symptoms is also highly individualized. Unfortunately, there is no single treatment that improves bloating for all, and no standard treatment strategy. From a diet standpoint, individuals should eliminate carbonated beverages, such as soda and beer. Chewing gum, drinking from a straw, and sucking on hard candies should be avoided to prevent excess air swallowing. Sugar free gum and hard candies should also be avoided as they may have mannitol or sorbitol as sweeteners which can cause flatulence – as do many artificial sweeteners. Foods such as cauliflower, broccoli, cabbage, beans, and bran should be avoided. Further, it is reasonable to try a dairy-free or gluten-free diet for a short period of time to see if symptoms improve. Lactaid milk or non-dairy milk (i.e. soy or almond milk) can be used as an alternative. One diet in particular that can be helpful is the low FODMAP (fermentable oligo-, di-, and monosaccharides and polyols) diet. This diet, which has been shown to help some people with IBS, involves cutting out certain foods that are poorly absorbed and that can result in gas-related symptoms. Meeting with a dietician for specific advice can help. Importantly, if a low FODMAP diet is pursued, it is crucial to systematically add food back after the initial elimination phase, to avoid developing nutritional deficiencies.

  Simethicone products have been promoted as treatment for bloatingbut unfortunately their effectiveness has not been convincing. Additionally, based on current research, prebiotics or probiotics cannot be recommended for the treatment of gas-related symptoms, as their effectiveness has also not been convincing.

  Individuals with IBS may benefit from symptomatic therapy for “gas pains” by using antispasmodic therapy such as dicyclomine or hyoscyamine under the tongue. Additionally, individuals who experience bloating in the setting of a disorder of gut-brain interaction, such as IBS or FD, may experience improvement with a “neuromodulator” medication, which can help to decrease symptoms due to overly sensitive nerves in the gastrointestinal tract; psychologic-based therapies, such as cognitive behavioral therapy (CBT) can also help in these situations.

  Treating constipation can help improve symptoms of bloating in some people. This can be done with over-the-counter medications, but sometimes requires treatment with a prescribed medication, many of which have been shown to improve bloating in some patients with constipation, including those with IBS-C. Additionally, for those with pelvic floor dysfunction, symptoms of bloating can improve with pelvic floor physical therapy.

  Some patients with bacterial overgrowth may see improvement from the use of antibiotics to reduce the number of bacteria in the small intestine, thereby reducing gas production. However, it is important to be careful about using antibiotics unnecessarily and too frequently, and the decision to treat with an antibiotic should be made in conjunction with a knowledgeable healthcare provider. Importantly, individuals with presumed SIBO do not always improve with antibiotic treatment.

  Finally, if symptoms persist or fail to respond to one or more of strategies mentioned above, specialized medical help, such as referral to a gastroenterologist, should be sought.

Important Points

• What are the important points to know about belching, bloating, distension and flatulence?

  • Belching and flatulence are normal body processes.
  • Abdominal bloating and distension are common symptoms, but may warrant medical evaluation if symptoms become bothersome and recurrent or chronic.
  • Gas-related symptoms can occur as a result of several medical problems, particularly those related to the gastrointestinal tract, but symptoms can also occur when testing is normal.
  • There is no universally effective treatment for gas-related symptoms.
  • Diet modification is a reasonable first step for treating gas-related symptoms.
  • Constipation is a common cause for abdominal bloating and distension, including irritable bowel syndrome and pelvic floor dysfunction.
  • Persistent symptoms or increasing frequency or severity of symptoms should prompt medical attention.

Author(s) and Publication Date(s)

Michael Levitt, MD, Veteran Affairs Medical Center, Minneapolis, MN, and Larry Szarka, MD, Mayo Graduate School of Medicine, Rochester, MN – Published June 2004.

Ronak Modi, MD, and Harris R. Clearfield, MD, MACG, Drexel University College of Medicine, Philadelphia, PA – Updated July 2013.

Elizabeth Huebner, MD, FACG, Washington University School of Medicine, St. Louis, MO – Updated January 2022.

David J. Cangemi, MD, FACG, Mayo Clinic Jacksonville, Jacksonville, FL and Amulya Konda, MD, HCA Healthcare, Tallahassee, FL – Updated July 2026.

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