Stomach Bloating: Causes, Symptoms and Relief Techniques
Bloated stomach? Learn about the common causes of stomach bloating and discomfort, as well as effective techniques for relieving symptoms and preventing recurrence.
Feeling bloated? You're not alone. Abdominal bloating and gas are among the most common digestive complaints that doctors hear from patients.
A recent survey that included close to 90,000 people found that about 14% of all Americans reported experiencing bloating in the previous seven days. And among bloating sufferers, close to 60% reported never having sought medical care for this problem. In other words, most people who experience bloating seem to have resigned themselves to just dealing with it on their own.
“Bloating” is term that people often use to refer to different experiences. For some, “bloating” actually means “distension,” or a waistline that protrudes significantly from its more typical, flatter baseline. This type of distended belly bloating bothers some people largely because of how it looks. They may think a protruding tummy makes them look "pregnant." Others are frustrated when that swollen stomach sticks around even after weight loss.
But for others, bloating is less about looks and more about discomfort. “Bloating” in this case can often refer to a feeling of discomfort and overfullness that is not commensurate with what or how much they eat. This subjective feeling of fullness, tightness or discomfort may or may not actually be accompanied by a visibly distended abdomen.
Often, bloating can be accompanied by other gastrointestinal symptoms, and these can offer clues as to the nature and origin of the bloating. For example, patients may describe belching, nausea, early fullness or heartburn that accompany their bloated bellies, suggesting the nature of their bloating originates with a problem in the stomach. Others may describe flatulence (farting), lower abdominal gas pains or cramping or irregular bowel movements that accompany their bloated bellies, suggesting the nature of their bloating originates in the intestines.
If you're ready to get rid of abdominal bloating, here's what you should know.
What Is Stomach Bloating?
The terms bloating and abdominal distension are often used interchangeably. Technically, bloating is a temporary feeling of fullness, usually due to intestinal gas, while abdominal distension refers to a visible, measurable increase in the stomach's size. Passing gas, belching or having a bowel movement may or may not provide relief.
Bloating and distention are symptoms, however, not conditions of their own. There are dozens of conditions that may be accompanied by bloating and/or distension, ranging from lactose intolerance and constipation to more serious conditions like colorectal or ovarian cancer. While many causes of bloating are caused by or worsened by certain foods, not all bloating has a specific dietary culprit underlying. While most causes of bloating do originate somewhere in the digestive system, some, like hypothyroidism or endometriosis, do not.
All of this is to say that solutions to bloating are not one-size-fits-all. Social media is brimming with oversimplified infographics offering lists of foods purported to either cause or cure bloating. And these may or may not be relevant to the type of bloating you experience. If you're committed to getting to the bottom of your bloating, you and your doctor or GI-trained dietitian will need to do some detective work.
What Causes a Bloated Stomach?
Dr. Hardeep Singh, a gastroenterologist with St. Joseph Hospital in Orange, California, says bloating can develop from several causes. Dietary problems are the most common, he says, with intolerance of certain food products leading the way. A food intolerance, or food sensitivity, means your digestive system can't break down specific foods, which can lead to excess gas and bloating. "Typical intolerances include dairy, but people can be intolerant to almost anything," he says.
Dietary causes of bloating
Lactose intolerance is an extremely common cause of bloating accompanied by excess intestinal gas and often looser stools, and is triggered by consumption of dairy products that are high in milk sugar (lactose). These include milk (lattes and cappuccinos count), whey protein concentrate, ricotta or cottage cheese, ice cream and certain types of sweet treats, like caramels, dulce de leche, puddings, custards, milk chocolate, key lime and pumpkin pies. Symptoms typically kick in several hours after consuming the offending foods or drinks.
Fructose and sucrose, respectively, are sugars that occur naturally in certain sweeteners, fruits and vegetables; they can also be added to a variety of foods. Fructose or sucrose intolerances present similarly to lactose intolerance, but are triggered by different foods. Fructose is found in honey, agave nectar, mangoes, figs and apples. Sucrose is found in a very wide variety of fruits and vegetables, ranging from bananas and oranges to carrots and corn to beans and potatoes, not to mention countless other foods to which sugar is added.
FODMAPs. Other carbohydrates that can be poorly absorbed and happen also to be highly-fermentable by our guts’ resident bacteria may trigger bloating in susceptible people as well. These food components are collectively known by an acronym called “FODMAPs,” and they can appear in dozens of foods, from beans and cauliflower to garlic and onions to cherries and apples. FODMAP is an acronym that stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols; these are chemical names of various sugars and fibers that can be difficult for humans to absorb. Poorly absorbed and easily fermentable foods are broken down by bacteria in the bowel, leading to gas production.
Inulin. An especially common food additive called inulin or chicory root is an especially fermentable – and therefore gas-producing – type of fiber. It deserves its own mention since it is extremely prevalent in processed foods and dietary supplements, especially ones marketed as sugar free, low carb, keto or containing “prebiotics.” You’ll find inulin in everything from protein bars, breakfast cereals and yogurts to protein powders, greens powders, herbal coffees, New Orleans-style coffees and eat-the-whole-pint low calorie ice creams. Certain foods, like jicama and Jerusalem artichoke (sunchoke) are naturally concentrated sources of inulin, while other foods like wheat, onions, garlic contain smaller amounts of it.
Other causes of stomach bloating
Another type of bloating may not be linked to what you eat but rather how you eat: swallowing air, or aerophagia. Aerophagia can result from eating too fast, talking while eating, chewing gum or chugging water – though it may also occur during exercise, sleeping or as the result of subconscious swallowing tics, especially among people who experience anxiety.
Swallowing air from eating too fast, chewing gum or using a straw is among the most common eating-related causes of bloating, says Cassie Vanderwall, a registered dietitian in the department of clinical nutrition at UW Health in Wisconsin.
When it comes to aerophagia, carbonated drinks may be friend or foe, depending on the person. Drinking soda or seltzer can make some people swallow excess air, thereby worsening their bloating. However, other people find that fizzy drinks help alleviate their bloating by inducing belching, and therefore actually relieving pressure caused by gas buildup in the stomach.
Farting and belching are also closely related to bloating. Belching or burping is caused by swallowed air that collects in the stomach. Passing rectal gas, or flatulence, is usually a combination of swallowed air and gas caused by bacteria in your colon forming around undigested carbohydrates.
Another common causes of bloating is constipation. If you're bothered by a rock-solid stomach with abdominal distension that builds as the day progresses and is relieved – or partially relieved – by pooping, constipation is a very likely cause. People who suffer from constipation-related bloating typically complain of feeling bloated, distended and extremely flatulent every night, regardless of what they’ve eaten for dinner. With constipation, normal intestinal gas gets trapped behind slow-moving poop and can build up, causing gas pain.
Constipation-related bloating generally does not respond adequately to elimination diets. When the stool burden – or amount of retained stool in the colon – is exceptionally high, eating very high fiber foods may actually make this type of bloating worse, not better. This is because all the fiber that goes in must come out, and if the bowel is already retaining a backlog of previously-consumed fiber, putting more dietary residue into a clogged pipeline will only make the problem worse.
There are many possibilities when it comes to causes for bloating. Conditions that cause bloating include:
H. pylori infection. A common bacterium called Helicobacter pylori causes infection in the digestive tract and is related to peptic ulcers and stomach cancer. About 30% to 40% of people in the United States get an H. pylori infection sometime in their life, the National Institutes of Health reports. H. pylori infection is thought to be spread in multiple ways, such as drinking unsanitary water or by passing from person to person. It can be diagnosed with blood tests, stool cultures or an upper endoscopy exam.
Delayed stomach emptying: A too-slow-to-empty stomach can cause bloating, and it is often accompanied by nausea, acid reflux, loss of appetite and/or early satiety (feeling full from a smaller than usual portion.). This condition, called gastroparesis, may be on the rise as part of a common constellation of lingering post-COVID symptoms that involve dysfunction of the autonomic nervous system.
Small intestinal bacterial overgrowth (SIBO). Harboring too many bacteria in the small intestine – a segment of your gut that is supposed to be relatively free of them – can produce significant amounts of bloating, particularly following meals high in FODMAP-containing foods, simple starches or sugars and/or high fat foods. Bloating typically onsets within an hour of consuming an offending food, and may be accompanied by a host of other upper or lower gastrointestinal symptoms, including a change in your normal bowel patterns or the appearance or caliber of your stool. SIBO can sometimes induce a deficiency in vitamin B12. Prescription antibiotics are the only evidence-based treatment for SIBO.
Disorders of the brain-gut interaction (DGBIs). When the nerves involved in two-way communication between the digestive tract and the brain are over-responding to stimuli, including the presence of even “normal” amounts of gas, stool or food portions, it can result in feelings of bloating or even visible distension. Often these conditions are more commonly seen in people who also experience anxiety and depression, but they are decidedly not all in your head, nor are they caused by stress. "Don't underestimate the psychological impact on bloating," says Dr. Charlotte Smith, an urgent care physician at Penn Medicine in Philadelphia who has seen many patients with significant bloating and GI upset due to stress and anxiety alone. There are many treatment options for DGBIs that impact the stomach (functional dyspepsia) or the intestines (irritable bowel syndrome), including medications, supplements, diet modifications and/or positive psychology interventions aimed at addressing the brain-gut communication axis. IBS is a chronic condition that affects the gastrointestinal tract characterized by pain in addition to altered bowel patterns. The International Foundation for Gastrointestinal Disorders reports that IBS affects between 25 and 45 million people in the United States; and an estimated 10% to 15% of the population worldwide has IBS. Growing evidence supports the value of trialing a low-FODMAP diet to help identify food triggers that may worsen your IBS symptoms. Consult a registered dietitian if you're considering adopting a low-FODMAP diet so you can receive guidance as to how to briefly eliminate potentially bothersome foods and how to systematically reintroduce them in order to pinpoint symptom triggers.
Celiac disease. An immune-system mediated intolerance to the protein gluten, called celiac disease, can cause noticeable bloating in addition to a host of other symptoms that affect the digestive tract and beyond. Foods containing wheat, rye or barley, such as pasta, bread and flour, or beer, trigger an immune response that damages the small intestine in affected people. It can take up to a day or two for celiac-related belly bloating to deflate. Gas may be particularly foul-smelling. Other symptoms associated with celiac disease can include changes in bowel movements or regularity, abdominal pain, iron deficiency, unintentional weight loss, skin rashes, headaches, joint pain or fatigue. A strict, lifelong gluten-free diet is the only treatment for celiac disease and consulting a knowledgeable dietitian is a must for people newly diagnosed. If you suspect you may have celiac disease, do not eliminate gluten-containing foods before seeing a gastroenterologist for testing, as the condition can only be diagnosed when you are consuming gluten as part of your usual diet.
Certain cancers: Tumors in the stomach, colon or ovaries may offer very few signs of their existence, especially in the earlier stages. Bloating is one of the earlier presenting symptoms of ovarian cancer, and it is a constant, persistent type of visible distension that never ebbs and flows. Colon cancer may present with bloating accompanied by new onset constipation and/or blood in the stool, and its prevalence is steadily increasing in the under 50 set. While many of the more common causes of bloating are indeed medically benign, even younger adults experiencing bloating accompanied by new onset constipation without having changed their diet should mention the issue to their doctor just to be on the safe side. This is especially true if you have a family history of breast, ovarian, pancreatic, prostate or colorectal cancer – or if you know yourself to be a carrier of the BRCA1 or BRCA2 genes.
Inflammation of the stomach. Also called gastritis, inflammation of the lining of the stomach can have many sources, with bacterial infection related to ulcers being among the most common. Overuse of pain relievers and drinking too much alcohol can also cause gastritis.
Stomach Bloating Explained
You can feel overfull when you hit up against the limits of your stomach’s natural ability to expand, or stretch, in response to eating a meal. Your stomach muscle is about the size of a fist at rest, but its muscular walls are designed to expand quite a bit to accommodate large amounts of food; this function is called “gastric accommodation.” Until the stomach completes its work of churning and breaking down food with digestive enzymes, it's natural to feel temporarily full after a substantial lunch or supper, though overdoing it with portions can make you feel uncomfortably full.
In some cases, however, the stomach may have impaired stretchiness that makes you feel as though you’ve overeaten even when you’ve eaten only a modest amount; this is called impaired gastric accommodation. Therefore, one of the first steps in relieving this type of bloating is to consume smaller portions more frequently rather than fewer, larger meals. There are some over-the-counter herbal remedies that can help with this type of bloating as well.
Visible distension – or a “pregnant” looking appearance – can often result from abnormal nerve reflexes that govern how the diaphragm and abdominal wall muscles coordinate in response to food or gas moving through the gastrointestinal tract. These abnormal reflexes can result in an exaggerated protrusion of the abdomen after eating, drinking liquids or harboring even “normal” amounts of intestinal gas. This type of neuromuscular dysfunction is sometimes treated with a therapy called biofeedback, or in some cases with nerve modulating medications.
Of course, a belly that isn't perfectly flat 24 hours per day is perfectly normal; our abdominal walls are stretchy by design so that they can accommodate multiple organs, the varying contents of our digestive tracts and bladders, and for some people, the uterus as well. Gestating children would be an impossibility if the abdominal wall was not pliable!
Sometimes, patients embarking on weight-management programs who don't develop the six-pack abs they've been striving for may complain of bloating, when that's not really the issue, Vanderwall notes. Similarly, people with body dysmorphia, a mental health condition characterized by hyper-fixation on perceived flaws in one’s appearance, will often complain of ‘bloating’ or distension that is not necessarily perceptible to others.
Latest Bloating Contributor: COVID-19
COVID-19 infection can cause digestive problems as well.
“With active COVID, we have seen patients with some GI symptoms: nausea, vomiting, bloating and those kinds of things,” says Dr. Greg Vanichkachorn, director of Mayo Clinic's COVID Activity Rehabilitation Program. That can happen with almost any viral illness, he notes, like stomach flu, “which can cause substantial stomach and digestive issues.”
Medications to treat active COVID-19 may contribute. “Some of the medicines we use can definitely affect the gut,” Vanichkachorn says. “Some antibiotics used early on for complicated infections can destroy the gut bacteria.” Steroids and other drugs can affect the GI system as well as the rest of the body, causing abdominal pain, bloating, constipation and food sensitivity.
Now, long COVID is creating persistent gastrointestinal woes. “What has been more surprising is that as we have gotten more into evaluating long COVID, we have seen that there are a fair number of patients who have been reporting ongoing GI problems,” Vanichkachorn says. “In some studies, 16% of patients report having new GI symptoms even 100 days or more after their infection, things like abdominal pain, constipation, vomiting and diarrhea. We’ve also heard about problems with excessive gas and the bloating sensation.”
Some patients with long COVID continue to experience GI symptoms for eight months and more on follow-up, according to an evidence review published in August 2022.
Long COVID and Food Sensitivities
New food sensitivities may arise in patients after COVID-19. “So they didn’t have any problems consuming, say, dairy products or, or have troubles with sugar,” Vanichkachorn says. But afterward, they find themselves having a very limited diet that they can tolerate. We have some patients who are just eating Cheerios and yogurt and that’s all they can really stomach.”
Ongoing problems with taste and smell can also throw off patients’ appetites, he notes. “If we’re not careful, it can really get into a situation where they’re not eating enough and developing malnutrition, with electrolyte problems.”
Patients with long COVID describe a constellation of GI symptoms. “It can have a lot of functional impacts,” Vanichkachorn says. “I have some patients who, for example, have really severe, bloody stool, diarrhea and incontinence issues that keep them from leaving home and going to work.”
Figuring out how to treat COVID-related GI symptoms is an issue. “Most of the time we’ll start with things like a bland diet, probiotics and adequate hydration,” Vanichkachorn says. Probiotics may help promote the regrowth of healthy gut bacteria, he says, although patients’ results have been mixed. “But it’s worth a shot now.”
Such patients undergo a gastroenterology evaluation. “They go through testing like colonoscopies to see if there’s anything else going on, or testing to see if there are problems with how the gut moves because we’ve seen that occur in neuropathy issues, which we’ve also seen quite a bit with long COVID, too.”
Whether and when GI symptoms like bloating resolve are uncertain. “Some get resolution, but the patients I have right now who have these significant GI issues really seem to be not resolving with time,” Vanichkachorn says. “So I’m not comfortable telling people: OK, this is going to go away with time. I think we need to have more research on the GI illness for those with long COVID and hopefully develop some treatments.”
Which Foods Affect Bloating?
Some problem foods are more likely to cause bloating, while other foods may help prevent it.
Carbohydrates. Certain carbs are more likely to lead to abdominal discomfort. These difficult-to-digest carbs are known as FODMAPs, and "these complex carbohydrates in our diets are associated with gas and bloating," Singh says. High FODMAP foods include wheat, garlic and onions.
Fiber. Soluble fiber from processed, high-fiber cereals and snack foods may increase bloating. Although a soluble fiber called inulin is considered healthful, it's also been found to increase bloating and gas. Onions, garlic, wheat, bananas and some other fruits and veggies contain inulin. However, insoluble fiber, which doesn't absorb water, may help relieve bloating. Bran, seeds and fruit and vegetable skins are prime sources of insoluble fiber, which speeds up food's journey through the intestines and limits gas production.
Sugars. Simple carbohydrates such as lactose or fructose and sugar alcohols, such as mannitol and xylitol (used to sweeten sugar-free candy and chewing gum) can trigger bloating. Foods that contain high fructose levels include corn syrup, certain fruits – such as apples, mangoes, watermelon, cherries and pears – and many sodas, snacks and condiments. Non-bloating fruits include most types of berries, pineapples, oranges and grapes. Using pure maple syrup as a sweetener may also cause less bloating than other sweeteners.
Beans. It's no myth: kidney beans, black beans, baked beans and others really do promote gas and bloating. Beans are a FODMAP food because they contain oligosaccharides and a lot of fiber, both of which can be difficult to digest, leading to gas and bloating.
Fatty foods. Greasy, fatty foods, such as fried chicken, cheeseburgers, onion rings and french fries can make you feel bloated as they linger in your stomach. Indigestion results from eating high-fat foods – or just eating in excess overall, Vanderwall says.
Carbonated drinks. As noted above, drinking soda, particularly through a straw, can make you swallow excess air, and too much air in your intestines leads to bloating. However, by making you belch, fizzy drinks like seltzer might actually relieve pressure caused by gas buildup in the stomach.
How Do Body Type and Weight Relate to Bloating?
Carrying extra belly fat can contribute to a more visibly distended waistline, but this is distinct from “bloating,” which is not a function of fat deposition or weight gain.
Possible culprits for excess abdominal fat include cigarette smoking and chronic alcohol consumption. Smoking affects where fat is deposited in the body, tending to favor the stomach. Heavy drinking has a similar effect, particularly in people assigned male at birth. A so-called "beer gut" can really occur with any type of alcohol used in excess.
In people assigned female at birth, having an apple-shaped body type means fat is more concentrated around the midsection, as opposed to pear-shaped body types. For people who experience menopause, the distribution of fat can also change and result in more concentration in the midsection
Contrary to popular diet claims, no foods or diets can target fat loss from the belly specifically. When you lose weight, you’ll lose body fat from all over. “Spot reduction” is not really a thing when it comes to weight loss.
How Does Sodium Relate to Bloating?
Often, people use the term “bloated” to refer to the puffy appearance they acquire following a salty meal or drinking too much alcohol. In these cases, the swollen appearance results from fluid retention within various tissues of the body, and often concentrates in the face, hands, fingers, legs and feet. It typically self-resolves within hours to a day when consuming lower sodium diet and drinking adequate water to expedite excretion of extra sodium from the system via the urine. You may even be able to speed up this process by drinking a high potassium beverage like coconut water.
Fluid retention is not the same thing as bloating or distention; the correct term for it is actually edema, which is not generally caused by problems in the digestive system except in the cases of advanced liver disease or a somewhat uncommon intestinal condition called protein losing enteropathy.
How Can You Get Rid of Bloating?
You don't have to live with bloating, and there's plenty you can do to alleviate bothersome or persistent symptoms. Trying to identify the nature of your bloating – starting with whether it seems digestively-driven or not, and if so, whether it seems more likely to originate in your stomach or your bowels – is a great place to start.
Keep a food and symptom journal. Pinpointing your personal bloating triggers is the first step. This should help you figure out whether specific food triggers are associated with your bloating, Singh says. Be precise about the foods you eat, the symptoms you experience and your bowel movements, including the times of day. Every detail matters, such as vitamins, alcohol and water intake, salad dressings and even midday treats like a piece of candy or two. This information will help your doctor or dietitian identify the cause of your bloating so you can make a plan to combat it.
Eliminate possible food triggers. If you've noticed a pattern, try removing the foods that appear to trigger bloating, one at a time, to see if gas and bloating improve. Look at labels to avoid ingredients that tend to bother you. Try temporarily cutting back on high-fiber foods that aggravate bloating.
Consider the role of meal patterns rather than specific foods. Sometimes, it’s not what you eat but how you eat that can contribute to bloating. Skipping breakfast and concentrating a full day’s worth of eating into two larger meals may not sit as well for some people than eating three modestly sized meals and one or two snacks. In other cases, eating large volumes of “roughage” from entrée sized salads, nighttime popcorn, nuts and berries may lead to more bloating than a diet characterized by more cooked, softer and less ‘volumetric’ foods. People prone to constipation or difficulty emptying their bowels completely often find one or both of these meal patterns to be problematic.
Treat constipation. If you do not move your bowels frequently or adequately enough to feel a true sense of relief, talk to your doctor about possible remedies to improve your stool output.
Make related lifestyle changes to reduce swallowed air. "Eliminate gum chewing and eat slower," Singh says. If you're an avid gum-chewer or hard-candy sucker, you're more likely to swallow excess air. Ditto for chugging or gulping water at the gym. Quitting smoking should also help.
Be mindful. Consider what could be causing your bloating and whether it's tolerable or it's time to make changes, Vanderwall says. A healthy, higher-fiber diet might be worth the trade-off in occasional bloating, for instance. However, she adds, if you believe that eating pace and food quantity are your problem, "this may be an area to explore and opportunity to become a more mindful eater."
Try gas-reduction remedies. Over-the-counter products such as Mylanta Gas and Gas-X contain simethicone, which breaks down gas bubbles and reduces pressure within the bowels. Adding Beano (alpha galactosidase), an over-the-counter supplement, to meals containing veggies and beans can also prevent gas from these healthy but fermentable foods. If you're lactose-intolerant, enzyme supplements like lactase can improve your digestion. There are over-the-counter supplemental enzymes available for fructose intolerance and prescription enzymes available for sucrose intolerance; a gastroenterologist can order breath testing to diagnose either of these conditions if they are suspected.
See a dietitian. "Registered dietitian nutritionists are well-prepared to accompany patients on their food- and nutrition-related journeys, including medical nutritional therapy for abdominal distension or bloating," Vanderwall says. There is even a subspecialty of GI-trained dietitians who have particular expertise in helping people identify and manage digestive symptoms, including bloating. The American Gastroenterological Association maintains a national database of GI-trained dietitians on its website.
Visit your doctor. If bloating and related digestive problems persist, your health care provider may suggest certain tests to rule out medical conditions. "Routine labs including testing for H. pylori infection or celiac disease should be considered," Singh says, and if indicated, your doctor may recommend an abdominal ultrasound or endoscopy to have a look at what's happening inside your belly. In some cases, antibiotics can relieve bloating from bacterial overgrowth.
It's possible that serious medical conditions may be the underlying cause of bloating, so the bottom line is: If issues persist, see a gastroenterologist, Singh says.
"People need to realize that this is not normal,” Vanichkachorn emphasizes. “So if patients are worried about any symptom, whether it may be related to COVID or not, they should go ahead and try to find care.”