Passing gas up to 20 times a day, including both burps and flatulence, is completely normal. If you’re noticing more than that, or if the frequency has recently changed, the cause is almost always one of two things: you’re swallowing too much air, or bacteria in your gut are fermenting undigested food. Often it’s both at once.
The Two Ways Your Body Makes Gas
Your digestive system produces gas through two distinct mechanisms, and each one shows up differently.
The first is swallowed air. Every time you eat, drink, or swallow saliva, a small amount of air goes down with it. Some of that air comes back up as a burp. The rest travels into your intestines and eventually exits as flatulence. If you’re mostly dealing with burping, swallowed air is the likely culprit.
The second is bacterial fermentation. Food particles your body can’t fully absorb pass into the large intestine, where bacteria break them down and release hydrogen and carbon dioxide in the process. Other bacteria consume that hydrogen and produce methane or sulfur-containing gases, which are responsible for the smell. If your main problem is frequent or foul-smelling flatulence, fermentation is doing the heavy lifting.
Habits That Make You Swallow Extra Air
Certain everyday habits dramatically increase the amount of air you take in. Eating too fast is one of the most common. When you rush through meals or talk while chewing, you swallow significantly more air with each bite. Other contributors include chewing gum, sucking on hard candy or lollipops, drinking through a straw, smoking, and drinking carbonated beverages.
The fix here is straightforward: slow down your eating, make sure you’ve swallowed one bite before taking the next, and sip from a glass instead of using a straw. Save conversations for after meals rather than during them. If you chew gum regularly or sip sparkling water throughout the day, try cutting those out for a week and see if your burping drops off.
Foods That Fuel Fermentation
Certain carbohydrates are poorly absorbed in the small intestine, so they arrive in the large intestine mostly intact, where bacteria feast on them and produce gas. These are sometimes grouped under the term FODMAPs, and they show up in foods you probably eat every day:
- Fructans and GOS: found in wheat, rye, onions, garlic, and legumes like beans, lentils, and chickpeas
- Lactose: found in milk, soft cheeses, and yogurt
- Fructose: found in honey, apples, and anything sweetened with high-fructose corn syrup
- Sugar alcohols (sorbitol and mannitol): found in some fruits and vegetables, and used as artificial sweeteners in sugar-free gum and candy
You don’t need to avoid all of these permanently. Most people have trouble with only a few categories, not all of them. A simple approach is to keep a food diary for a couple of weeks, noting what you ate and when the gas was worst. Patterns tend to emerge quickly. Beans and onions are among the most common offenders, but dairy is a close runner-up, especially if you’ve become less tolerant of lactose over time (which happens naturally to many adults).
When Your Gut Bacteria Are Out of Balance
Sometimes the issue isn’t what you’re eating but what’s happening inside your gut. When the balance of bacteria shifts, certain populations can overproduce gas. Sulfate-reducing bacteria, for example, are the main producers of hydrogen sulfide in the gut. That’s the gas responsible for a rotten-egg smell. At high concentrations, hydrogen sulfide can irritate the gut lining and contribute to inflammation, creating a cycle where the gas itself makes the problem worse.
A condition called small intestinal bacterial overgrowth (SIBO) involves bacteria growing in a part of the gut where they normally shouldn’t be in large numbers. SIBO tends to cause significant bloating and gas, more so than pain. Irritable bowel syndrome (IBS), by contrast, is typically more pain-dominant, though it also causes gas and bloating. The two conditions overlap frequently, and a breath test that measures hydrogen and methane levels can help distinguish them.
Probiotics have shown meaningful results in reducing flatulence and bloating in clinical trials, both short and long term. They work by helping restore a healthier bacterial balance. Fermented foods like yogurt, kefir, sauerkraut, and kimchi provide some of the same bacteria, though in less concentrated amounts than supplements.
Over-the-Counter Options That Actually Work
Not every product on the pharmacy shelf lives up to its promises. Here’s what the evidence supports:
Alpha-galactosidase (sold as Beano) is effective at reducing bloating and gas specifically from fermentable carbohydrates like beans, bran, and fruit. You take it with your first bite of a problem food, and it helps break down the carbohydrates before bacteria get to them. If beans or cruciferous vegetables are your main trigger, this is worth trying.
Simethicone (found in Gas-X) is widely recommended, but studies have not shown a benefit for ordinary flatulence. It works by breaking up gas bubbles in the stomach, which can help with that uncomfortable “full of air” feeling, but it doesn’t reduce the total amount of gas your body produces.
For foul-smelling gas specifically, bismuth subsalicylate (Pepto-Bismol) binds more than 95 percent of sulfur-containing gases in the gut. It won’t reduce how often you pass gas, but it can dramatically cut the odor. Oral activated charcoal, despite its popularity, has inconsistent evidence and isn’t well supported for gas reduction.
Signs Something More Serious Is Going On
Excessive gas on its own is almost never dangerous. But certain accompanying symptoms shift the picture. If your gas comes with unintentional weight loss, blood in your stool, persistent vomiting, ongoing diarrhea or constipation, or frequent heartburn, those combinations can point to conditions like celiac disease, inflammatory bowel disease, or other digestive disorders that need proper evaluation.
A useful threshold: if you’re passing gas or burping more than 20 times a day and the problem persists for several weeks despite dietary changes, that’s a reasonable point to get checked out. Most of the time, the answer will be something manageable, but identifying conditions like SIBO or lactose intolerance early makes them much easier to treat.