Bloating and distension are common IBS symptoms that are similar, and as such are often used interchangeably by many people, including doctors. However, they are not the same thing -- there are some key differences between these two very frustrating symptoms!
While bloating refers to a swelling feeling in the stomach (it can be experienced as having an expanding balloon inside of you), distension is a swelling in the abdomen that can not only be felt but seen and even measured (2,3).
Bloating affects most IBS patients -- in fact, over 90% of IBS patients report bloating as a symptom and tend to feel that it's one of the most frustrating ones at that. It also extends to the average person without IBS, as 10% to 30% of the overall population also reports struggling with bloating. It affects women more frequently than men, even when bloating related to menstruation is ruled out. People who have IBS-C (constipation-predominant IBS) tend to report bloating and distension more often than those with IBS-D or IBS-M (diarrhea-predominant IBS or mixed IBS), and distension particularly is often is linked with slow transit of fecal matter through the intestines (1,3).
Many people experience abdominal distension at the same time as bloating, but not always. Only about half of people who report abdominal bloating also report distension (3).
Although there are differences between bloating and distension, they do share some things in common. Both are highly frustrating symptoms that rank among the most complained about symptoms, and can be linked with other gas-related issues, such as burping, passing gas, or inhaling air. They can both get worse as the day wears on, are frequently worsened by mealtime, and often get better overnight (2, 3).
Distension can be measured simply by using a tape measure at various intervals. In research studies, for more precision, sometimes technology called ambulatory abdominal inductance plethysmography, or AIP, is used to record minimal changes in measurement throughout the day. Using this technology, studies demonstrate that the abdomen can increase by as much as 12 cm in certain people (1,3).
While research has explored different possible causes of bloating and distension, there have been no conclusive results. Some possible explanations include too much gas in the intestines, food intolerance, an imbalance in the microbiome of bacteria in the intestines (sometimes due to antibiotics), or increased sensitivity to movement in the GI tract. It’s also been proposed that small intestinal bacterial overgrowth or SIBO could be responsible, as well as physical abnormalities such as a curved lumbar region that reduces the body’s space to hold gas (2).
While there is no one treatment to put a stop to bloating and distension, there are things your doctor can suggest to help you manage them by managing the overall symptoms of your digestive disorder. By describing your symptoms as accurately as possible, including where the swelling is felt, when it is at its worst, and if there are any other symptoms such as nausea or burping associated with them, your doctor will help you discover which of the two issues you are dealing with. After likely running some tests to rule out other conditions, he or she may recommend various treatments including antispasmodics to relax the bowel muscles, probiotics to balance bacteria in the intestines, or various medications, including antibiotics, medications to increase the water in stools, or medication to increase gut motility time. A low FODMAP diet may also be recommended, as it has been shown to help alleviate bloating and distension (1, 2).
Although very common, bloating and distension are frustrating symptoms that can be difficult to eradicate, for many people, including those who suffer from IBS and other GI disorders and those who do not. They may be similar, but distinguishing between bloating and distension is important, as they can be caused by different issues. It’s important to work with your doctor to figure out if it is indeed bloating, distension, or both that is affecting you. Together, you can get to the root cause to help mitigate symptoms with the correct treatment (2,3).
- Barbara Bolen, Ph.D., “Abdominal Distension and Digestive Disorders,” verywellhealth.com, Dotdash, reviewed on October 26, 2020, https://www.verywellhealth.com/what-is-abdominal-distension-1944868.
- “Understanding Bloating and Distension,” iffgd.org, International Foundation for Gastrointestinal Disorders, accessed September 7, 2021, https://iffgd.org/gi-disorders/symptoms-causes/bloating-and-distension/.
- Dr. Jane Varney, “Abdominal bloating vs. distension -- what’s the difference?,” monashfodmap.com, Monash University, published May 7, 2018, https://www.monashfodmap.com/blog/abdominal-bloating-vs-distension-whats-difference/#:~:text=Bloating%20refers%20to%20the%20sensation,increase%20in%20measured%20abdominal%20size.