Passing gas between 14 and 23 times a day is completely normal. If you’re noticing more than that, or your gas feels uncomfortable and persistent, the cause almost always traces back to what you’re eating, how you’re eating it, or how your gut bacteria are processing what arrives in your large intestine.
How Your Body Produces Gas
Gas comes from two sources. The first is air you swallow, which produces burping and some flatulence. The second, and far more significant source, is bacterial fermentation in your large intestine. When food isn’t fully digested or absorbed in your small intestine, the bacteria in your colon break it down. That fermentation process releases hydrogen, carbon dioxide, and sometimes methane. The more undigested material that reaches your colon, the more gas your bacteria produce.
This is a normal, healthy process. Your gut bacteria are supposed to ferment fiber and other carbohydrates. The issue is when the volume of fermentable material overwhelms the system, or when something shifts the balance so that more gas is being produced than your body can quietly absorb or pass.
Foods That Cause the Most Gas
Certain carbohydrates are poorly absorbed in the small intestine, which means they arrive in the colon almost intact and become fuel for gas-producing bacteria. These fall into a group called FODMAPs, short-chain carbohydrates found in a wide range of everyday foods. The biggest offenders include beans and lentils, wheat-based products like bread and cereal, dairy (milk, yogurt, ice cream), and certain fruits and vegetables. Apples, pears, cherries, peaches, onions, garlic, asparagus, and artichokes are all high on the list.
Fiber plays a role too, but not all fiber is equal. Soluble fibers that dissolve in water, like those found in oats, barley, and inulin (added to many “high fiber” processed foods), are readily fermented by gut bacteria and produce significant gas. Insoluble fibers like wheat bran and cellulose don’t dissolve in water and are poorly fermented, so they tend to cause less gas. If you recently increased your fiber intake through supplements, protein bars, or a diet change, that’s a very common trigger.
Sugar alcohols are another frequent culprit that people overlook. These are sweeteners used in sugar-free gum, mints, protein bars, and diet foods. Sorbitol, xylitol, mannitol, and maltitol cannot be fully digested or absorbed, so they pass into the colon where bacteria ferment them rapidly. If you chew sugar-free gum regularly or eat “no sugar added” snacks, this alone could explain a noticeable increase in gas.
Swallowed Air Adds Up
Not all gas comes from fermentation. You swallow small amounts of air constantly, but certain habits increase that volume significantly. Eating too fast, chewing gum, sucking on hard candies, and drinking through straws all push extra air into your digestive tract. Carbonated drinks add gas directly.
The fix here is straightforward: chew food slowly, make sure you’ve swallowed one bite before taking the next, sip from a glass instead of a straw, and cut back on gum. These changes can reduce upper GI gas (mostly burping) within days.
Food Intolerances You Might Not Recognize
Lactose intolerance is one of the most common reasons for unexplained gas, and many people don’t realize they have it. When your body doesn’t produce enough of the enzyme that breaks down lactose (the sugar in milk), that lactose travels to your colon undigested and ferments. Most lactose-intolerant people can handle small amounts of dairy without symptoms, but once they cross a threshold of roughly 12 to 18 grams of lactose (about 8 to 12 ounces of milk), gas, bloating, and cramping kick in. A single large latte or bowl of ice cream can easily push past that line.
Fructose malabsorption works similarly. Some people absorb fructose poorly, and foods high in fructose (honey, certain fruits, high-fructose corn syrup) send unabsorbed sugar straight to the colon for fermentation. If you notice gas gets worse after fruit, juice, or sweetened drinks, this could be the reason.
When Gas Points to a Digestive Condition
Persistent, excessive gas that doesn’t respond to dietary changes can signal something beyond food choices. Small intestinal bacterial overgrowth (SIBO) occurs when bacteria that normally live in the large intestine colonize the small intestine instead. Because the small intestine handles most nutrient absorption, bacteria in the wrong location ferment food much earlier in the digestive process, producing large volumes of gas, bloating, and often diarrhea. SIBO is typically diagnosed through a breath test that measures hydrogen and methane levels after drinking a sugar solution.
Celiac disease is another condition where gas is a core symptom. Gluten damages the lining of the small intestine in people with celiac disease, impairing its ability to absorb nutrients. That undigested food then ferments in the intestines, producing excess gas and bloating. Celiac disease affects roughly 1 in 100 people, and many go years without a diagnosis because they attribute their symptoms to a “sensitive stomach.”
Irritable bowel syndrome (IBS) frequently involves excessive gas as well. People with IBS often have heightened sensitivity to normal amounts of intestinal gas, meaning even a standard volume of gas can feel painful and distended. A low-FODMAP diet, guided by a dietitian, is one of the most effective approaches for reducing gas in IBS.
Simple Changes That Reduce Gas
Start by identifying your triggers. Keep a basic food diary for one to two weeks, noting what you eat and when gas is worst. Patterns usually emerge quickly. Common discoveries include a daily protein bar loaded with sugar alcohols, a new fiber supplement, a large morning coffee with milk, or a habit of eating lunch in five minutes at a desk.
If beans, lentils, or cruciferous vegetables are the issue, cooking them thoroughly helps break down some of the compounds that cause fermentation. Introducing high-fiber foods gradually, rather than all at once, gives your gut bacteria time to adjust. Increasing fiber intake slowly over two to three weeks produces significantly less gas than a sudden dietary overhaul.
For lactose intolerance, switching to lactose-free dairy products or plant-based alternatives eliminates the problem entirely. Hard cheeses and yogurt are often tolerable because they contain less lactose than milk or ice cream.
Signs That Need Medical Attention
Gas on its own is rarely a sign of something serious. But if your gas comes alongside blood in your stool, unintentional weight loss, persistent diarrhea or constipation, a change in how often you have bowel movements, or ongoing nausea and vomiting, those combinations warrant a medical evaluation. Prolonged abdominal pain or chest pain alongside gas calls for immediate care. And if gas is severe enough to interfere with your daily life and doesn’t improve with dietary changes, testing for conditions like SIBO, celiac disease, or food intolerances can identify what’s driving it.