Digestive Health Irritable Bowel Syndrome Symptoms Bloating and Distension in IBS By Barbara Bolen, PhD Barbara Bolen, PhD Twitter Barbara Bolen, PhD, is a licensed clinical psychologist and health coach. She has written multiple books focused on living with irritable bowel syndrome. Learn about our editorial process Updated on May 28, 2021 Medically reviewed by Robert Burakoff, MD, MPH Medically reviewed by Robert Burakoff, MD, MPH on May 06, 2021 LinkedIn Robert Burakoff, MD, MPH, is board-certified in gastroentrology. He is the vice chair for ambulatory services for the department of medicine at Weill Cornell Medical College in New York. Learn about our Medical Review Board Print Table of Contents View All Table of Contents Bloating Distension Causes Treatment Frequently Asked Questions Bloating and abdominal distension, which can affect anyone, are especially common with irritable bowel syndrome (IBS), and they can be among the most persistent symptoms of the condition. PhotoAlto / Odilon Dimier / Getty Images Bloating Bloating is defined as the perception of increased pressure in the abdomen. Bloating is a fairly universal phenomenon, reported more frequently by females than males, with an estimated 16 to 31% of the general population experiencing it at some point. Up to 90% of people who are diagnosed with IBS report bloating, and the percentage is even higher for those with constipation-predominant IBS (IBS-C). While it's most common in IBS-C and mixed-type IBS, about half of those with diarrhea-predominant IBS (IBS-D) experience it, too. However, bloating isn't listed as part of the Rome IV criteria for diagnosing IBS. What Is Rome IV? Rome IV includes diagnostic criteria for IBS. It is periodically updated to incorporate new research. The first version came out in 1988 from the 13th International Congress of Gastroenterology in Rome, Italy, hence the name "Rome criteria." Distension Distension differs from bloating in that it involves a measurable change in abdominal circumference (the measurement around your waist at the largest part). Distension typically worsens as the day wears on. You may also find that your abdomen gets more distended after you have eaten. It's estimated that approximately half of all people who have IBS experience distension. Distension and bloating often occur simultaneously, but it is thought that they result from different bodily processes. Causes Studies show that excessive gas is responsible for about 25% of the bloating associated with IBS and other functional gastrointestinal (GI) disorders. Several underlying mechanisms are being investigated as possible causes of bloating in IBS. It's possible that many of them are interrelated. Some possible underlying mechanisms include: Disruption of the brain-gut axis: A complex interaction between the brain and gut bacteria suggests that psychological stress can impact the balance of bacteria and vice versa. Increased intestinal permeability ("leaky gut"): Improper function of the intestinal lining may allow bacteria and small molecules of partially digested food to leave the digestive system, trigger inflammation, and interfere with the balance of gut bacteria. Intestinal immune activation: Low-grade inflammation may be due in part to abnormal activity of the immune system. Visceral hypersensitivity: People with this problem tend to feel bloated and have other symptoms when the digestive system is only mildly irritated. It usually occurs without distension. Gastrointestinal dysmotility (impaired movement): This causes gas to get trapped in the first and middle parts of the colon. Impaired abdominal wall response to pressure: This occurs with chronic bloating and distension, as the reaction of the diaphragm and abdominal wall muscles to pressure from gas is the opposite of what it should be. Evidence also suggests that bloating may especially be a problem for people who have other digestive issues in addition to IBS. These include: Food intolerances: Often, malabsorption due to food intolerance leads to fermentation, which increases gas production. Small intestine bacterial overgrowth (SIBO): Excess levels of some bacteria may be responsible for carbohydrate fermentation. Bacterial imbalances: Some healthy bacteria in the digestive tract may decline, which can slow digestion. People who have IBS-C are more likely to have bloating and distension if it takes longer for digested material to travel through the colon. Bloating and Quality of Life Bloating has a negative impact on quality of life. In surveys, it runs neck-and-neck with abdominal pain as the most severe symptom of IBS. In one survey, a quarter of people with IBS-C ranked it as their most bothersome symptom. How to Balance Your Gut Flora IBS Symptom Relief Bloating is a notoriously difficult symptom to treat. However, you do have several options to explore to get rid of bloating. IBS is different for everyone, so expect to do a lot of experimentation before you find what works best for you, and try not to get frustrated when your experience doesn't match that of other people with this condition. IBS Medications No treatments are definitively proven to improve bloating in IBS. Common drugs that doctors may recommend include: Antispasmodic drugs, including Menoctyl (otilonium) and Bentyl (dicyclomine), may help calm spasms in the intestinal walls that can trap gas Antidepressants to help correct the brain-gut dysfunction, including tricyclics (TCAs) and selective serotonin reuptake inhibitors (SSRIs) Prosecretory drugs, a kind of prescription laxative, including Linzess (linaclotide) and Trulance (plecantide) Viberzi/Truberzi (eluxadoline), which alters the activity of certain cell receptors in the nervous system and improves symptoms of IBS-D Serotonergic agents such as Lotronex (alosetron), as the hormone/neurotransmitter serotonin is involved in digestive motility, sensation, and secretion Antibiotics, which may be helpful for those with SIBO, including Xifaxan (rifaximin) and Biaxin (clarithromycin) Bulk laxatives, available over-the-counter (OTC), to help you expel gas and feces Gax-X (simethicone), an OTC medication that can help you eliminate gas IBS Drug Treatment Options Other IBS Treatments While medications may help, they may not alleviate all of your symptoms. Many people with IBS include other types of treatments in their regimen, including: Dietary changes, especially a low-FODMAP diet or elimination of trigger foods Probiotic or prebiotic supplements, which may help balance gut bacteria Peppermint oil, which is a natural antispasmodic (see warning below) Psychological therapies including cognitive behavioral therapy, relaxation therapy, and hypnotherapy Exercise and physical fitness, which studies show may help ease symptoms While they've received less scientific attention than other types of treatments, some evidence supports the use of mind-body treatments for IBS. Warning: Peppermint Oil Peppermint oil is soothing to the muscle cells that line much of your GI tract, which can ease IBS symptoms. However, it can also relax the sphincter between your stomach and esophagus, which often leads to heartburn and reflux. To avoid this, be sure to take peppermint oil capsules that are enteric-coated, as the coating won't dissolve until it reaches your intestines. New IBS Treatment Guidelines Frequently Asked Questions What relieves IBS bloating? Peppermint tea may provide some immediate IBS relief along with relaxation and exercise. Treatments that may help over the course of several weeks include Linzess (linaclotide), probiotics, and antibiotics. Long-term relief, though, may require dietary changes and efforts to avoid constipation. Why does IBS make my belly swell? Constipation is the most common cause of IBS-related belly swelling, known as distension. This often results from problems with the function of gastrointestinal nerves and muscles. You may also experience bladder hypersensitivity, which causes abdominal swelling. How long does an attack of IBS bloating last? An IBS flare-up typically lasts two to five days. In addition to bloating, you might experience constipation or extreme diarrhea, cramping, and emotional symptoms such as anxiety. Was this page helpful? Thanks for your feedback! One of the most challenging aspects of having IBS is trying to figure out what's safe to eat. Our recipe guide makes it easier. Sign up and get yours now! Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit 16 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Lacy BE, Cangemi D, Vazquez-Roque M. Management of chronic abdominal distension and bloating. Clin Gastroenterol Hepatol. 2021;19(2):219-231.e1. doi:10.1016/j.cgh.2020.03.056 Safaee A, Moghimi-Dehkordi B, Pourhoseingholi MA, et al. 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Published 2013 Aug 26. doi:10.1371/journal.pone.0071834 Alammar N, Wang L, Saberi B, et al. The impact of peppermint oil on the irritable bowel syndrome: A meta-analysis of the pooled clinical data. BMC Complement Altern Med. 2019;19(1):21. Published 2019 Jan 17. doi:10.1186/s12906-018-2409-0 Mckay DL, Blumberg JB. A review of the bioactivity and potential health benefits of peppermint tea (Mentha piperita L.). Phytother Res. 2006;20(8):619-33. doi:10.1002/ptr.1936 Issa B, Morris J, Whorwell PJ. Abdominal distension in health and irritable bowel syndrome: The effect of bladder filling. Neurogastroenterol Motil. 2018;30(11):e13437. doi:10.1111/nmo.13437 Palsson OS, Baggish J, Whitehead WE. Episodic nature of symptoms in irritable bowel syndrome. American Journal of Gastroenterology. 2014;109(9):1450-1460.doi:10.1038/ajg.2014.181 Additional Reading Lacy BE, Cangemi D, Vazquez-Roque M. Management of chronic abdominal distension and bloating. Clin Gastroenterol Hepatol. 2021;19(2):219-231.e1. doi:10.1016/j.cgh.2020.03.056 Rome Foundation. Rome IV criteria: Appendix A: Rome IV diagnostic criteria for FGIDs. Updated January 16, 2016.