Passing gas 14 times a day is medically normal, and your body produces roughly two liters of intestinal gas every 24 hours. If you feel like you’re well beyond that, or if the gas comes with discomfort, bloating, or embarrassment, something in your diet, habits, or digestion is likely tipping the balance. The good news: most causes are fixable without medical intervention.
What Creates Gas in the First Place
Gas comes from two sources. The first is air you swallow, which tends to come back up as burping. The second, and usually the bigger contributor to flatulence, is bacterial fermentation in your large intestine. When your small intestine can’t fully break down certain carbohydrates, bacteria in your colon finish the job, producing hydrogen, methane, and carbon dioxide as byproducts. The more undigested material that reaches your colon, the more gas those bacteria generate.
Foods That Produce the Most Gas
Certain short-chain carbohydrates are poorly absorbed in the small intestine and ferment rapidly once they reach the colon. These are sometimes grouped under the term FODMAPs, and they’re found in a surprisingly wide range of everyday foods: beans, lentils, onions, garlic, wheat, apples, pears, dairy products, cauliflower, broccoli, and Brussels sprouts are common offenders. Artificial sweeteners like sorbitol and mannitol (often found in sugar-free gum and candy) also ferment aggressively.
Fiber is another major factor. High-fiber foods are genuinely healthy, but if you recently increased your intake, that alone can explain a dramatic uptick in gas. The key is to go slowly. Nutrition guidelines recommend increasing total fiber by no more than five grams per day until you reach your target. Drinking plenty of water alongside fiber helps keep things moving and reduces fermentation. If you jumped straight into a high-fiber diet, your gut bacteria need a few weeks to adjust.
Swallowed Air Adds Up Fast
You swallow small amounts of air every time you eat, drink, or talk. Certain habits amplify this significantly. Eating quickly, talking while you eat, chewing gum, sucking on hard candy, using straws, drinking carbonated beverages, and smoking all increase the volume of air entering your stomach. This condition, called aerophagia, typically causes more belching than flatulence, but some of that swallowed air does travel through to your intestines.
If your gas is mostly upper-GI (lots of burping, a full feeling in your stomach), look at these habits first. Slowing down at meals and cutting back on carbonation can make a noticeable difference within days.
Lactose and Other Food Intolerances
Roughly 57 to 65 percent of the global population has some degree of lactose malabsorption, making it one of the most common and underrecognized causes of chronic gas. When your body doesn’t produce enough of the enzyme that breaks down lactose (the sugar in milk), that lactose passes intact into your colon, where bacteria ferment it into gas, bloating, and often diarrhea.
The tricky part is that lactose intolerance exists on a spectrum. You might tolerate a splash of milk in coffee but react to a bowl of ice cream. A simple way to test this is to eliminate all dairy for two weeks and see if your symptoms improve, then reintroduce it and track what happens. The same approach works for other suspected triggers like wheat, onions, or legumes.
When a Gut Condition Is the Cause
If dietary changes don’t explain your symptoms, a few medical conditions are worth considering.
Small intestinal bacterial overgrowth (SIBO) occurs when bacteria that normally live in the colon colonize the small intestine. Those bacteria start fermenting food earlier in the digestive process, producing excess hydrogen or methane gas. Beyond flatulence, SIBO often causes bloating, abdominal pain, diarrhea (or sometimes constipation, particularly when methane-producing organisms are involved), and in more severe cases, weight loss or nutrient deficiencies. It’s diagnosed with a breath test that measures hydrogen and methane levels after you drink a sugar solution.
Irritable bowel syndrome (IBS) is another common culprit. People with IBS tend to produce more prolonged hydrogen gas in response to fermentable carbohydrates compared to people without the condition. IBS also involves heightened sensitivity in the gut, meaning normal amounts of gas can feel significantly more uncomfortable. If your gas comes alongside recurring abdominal pain that’s linked to bowel movements, along with changes in stool consistency, IBS is a likely explanation.
Celiac disease damages the lining of the small intestine and impairs absorption, sending more undigested food to the colon for fermentation. Chronic gas with diarrhea, fatigue, or unexplained weight loss warrants testing. Other less common causes include gastroparesis (delayed stomach emptying) and, rarely, blockages in the digestive tract.
Over-the-Counter Options That Help
A digestive enzyme called alpha-galactosidase (sold as Beano and similar products) breaks down the specific sugars in beans, lentils, and cruciferous vegetables before they reach your colon. You take it at the start of a meal, and it reduces the amount of fermentable material available to your gut bacteria. Clinical trials show it significantly reduces both the severity and frequency of bloating and flatulence, with improvement becoming evident within a few days. The effect does tend to fade after you stop taking it, so it works best as a tool for meals you know will be problematic.
For lactose intolerance, lactase enzyme supplements taken before eating dairy work on the same principle: they supply the enzyme your body underproduces. Simethicone (sold as Gas-X) works differently. It doesn’t prevent gas production but instead breaks up gas bubbles in your gut, which can relieve the pressure and discomfort.
Probiotics are a more complicated picture. Certain specific strains have shown real benefit for people with IBS-related bloating and gas, but the results are very strain-dependent. A general “probiotic blend” from the supplement aisle may or may not help. If you want to try one, give it at least four weeks before deciding whether it’s working.
A Practical Approach to Figuring It Out
Start with the simplest explanations. Keep a food diary for one to two weeks, noting what you eat and when gas is worst. Patterns usually emerge quickly: maybe it’s the lunchtime salad with raw broccoli and onions, or the protein bar sweetened with sugar alcohols, or the three cups of milk-based coffee. Cut the likely triggers for two weeks, then reintroduce them one at a time.
At the same time, check your eating habits. Eating more slowly, avoiding gum, and reducing carbonated drinks are low-effort changes that eliminate swallowed air as a variable. If you recently started eating more fiber or switched to a plant-heavy diet, give your gut four to six weeks to adapt before assuming something is wrong.
If none of that resolves the problem, or if your gas comes with abdominal pain, a sudden change in bowel habits, unintentional weight loss, or blood in your stool, those are signs that something beyond diet is going on and worth investigating with a doctor. For most people, though, the answer is somewhere in their daily meals and habits, and a few targeted changes can bring real relief.