Digestive Health Irritable Bowel Syndrome Symptoms Bloating and Distension in IBS By 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 Barbara Bolen, PhD Medically reviewed by Medically reviewed by Priyanka Chugh, MD on November 19, 2019 linkedin Priyanka Chugh, MD, is board-certified gastroenterologist with a background in internal medicine. She is an assistant professor at the Icahn School of Medicine at Mount Sinai. Learn about our Medical Review Board Priyanka Chugh, MD on November 19, 2019 Print Irritable Bowel Syndrome Overview Symptoms Causes Diagnosis Treatment Coping Nutrition PhotoAlto / Odilon Dimier / PhotoAlto Agency RF Collections / Getty Images In the not so distant past, medical professionals often thought that the bloating and distension frequently reported by their IBS patients were just products of an overly active imagination. If you have had the experience of having to loosen your belt as your day goes by, you know how off base these doctors were. Prevalence Bloating is a fairly universal phenomenon, as it is estimated that 16% to 30% of the general population reports that they suffer from bloating These numbers skyrocket when talking about IBS patients, with 80% to 90% of patients reporting bloating. Given these numbers, it is somewhat surprising that bloating is not even listed as part of the Rome III criteria for diagnosing IBS. Bloating Bloating is defined as the perception of increased pressure in the abdomen. Bloating is reported more frequently by women than men, but this may be due to differences in how the symptom is perceived by the different genders. Bloating is also more likely to affect patients with constipation-predominant IBS (IBS-C) and mixed type IBS than those with diarrhea-predominant IBS (IBS-D). This does not mean that bloating doesn’t affect IBS-D patients, in fact, bloating is a problem for almost half of all IBS-D patients. Distension Distension differs from bloating in that it involves a measurable change in the circumference of the abdomen. Distension typically gets worse as the day wears on. You may also find that your abdomen gets more distended after you have eaten. It is estimated that approximately half of all IBS patients experience distension. Distension and bloating often are experienced simultaneously, but it is thought that they result from different bodily processes. Causes Contrary to what you might think, excessive gas is not necessarily the reason behind bloating and distension. Several mechanisms that are being explored as possible contributors to bloating and distension are: Trapped gasVisceral hypersensitivityDysmotilityImpairment of the abdominal wall in responding to pressure There is also evidence that bloating may be a problem for sub-groups of IBS patients who suffer from: Carbohydrate intolerancesBacterial imbalancesSmall intestine bacterial overgrowth (SIBO) Effect on Quality of Life The symptom of bloating clearly negatively impacts one's quality of life. In surveys, bloating runs neck and neck with abdominal pain as the most severe symptom IBS patients must deal with. Bloating also appears to be the symptom least likely to respond to treatment. The symptom of bloating appears to go beyond just discomfort; one study found that bloating in IBS patients was related to decreased energy, decreased physical functioning, and a lowered of food intake. 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 Article 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. Agrawal A, Whorwell PJ. Review article: abdominal bloating and distension in functional gastrointestinal disorders--epidemiology and exploration of possible mechanisms. Aliment Pharmacol Ther. 2008;27(1):2-10. doi:10.1111/j.1365-2036.2007.03549.x Safaee A, Moghimi-dehkordi B, Pourhoseingholi MA, et al. Bloating in irritable bowel syndrome. Gastroenterol Hepatol Bed Bench. 2011;4(2):86-90. International Foundation for Gastrointestinal Disorders. Understanding bloating and distention. Updated October 2 2019. Sullivan SN. Functional abdominal bloating with distention. ISRN Gastroenterol. 2012;2012:721820. doi:10.5402/2012/721820 Dukowicz AC, Lacy BE, Levine GM. Small intestinal bacterial overgrowth: a comprehensive review. Gastroenterol Hepatol (N Y). 2007;3(2):112-22. Ringel Y, Williams RE, Kalilani L, Cook SF. Prevalence, characteristics, and impact of bloating symptoms in patients with irritable bowel syndrome. Clin Gastroenterol Hepatol. 2009;7(1):68-72. doi:10.1016/j.cgh.2008.07.008 Additional Reading Chang, L., Lee, O., Naliboff, B., Schmulson, M. & Mayer, E. "Sensation of bloating and visible abdominal distension in patients with irritable bowel syndrome." American Journal of Gastroenterology 2001 96:3341-3347. Quigley, E. “ Impact of Bloating and Distention in Irritable Bowel Syndrome: Have We Wandered too far From the Manning Creed?” Clinical Gastroenterology and Hepatology 2009 7:7-8.