Passing gas between 14 and 23 times a day is completely normal. If you’re consistently above that range, or if the volume and smell have noticeably changed, the cause almost always traces back to what you’re eating, how you’re eating, or how your gut is processing food. Less commonly, excessive gas signals an underlying digestive condition worth investigating.
How Gas Forms in Your Gut
Gas in your digestive tract comes from two sources: swallowed air and bacterial fermentation. When you eat, you swallow small amounts of air. Most of that exits as burps. The rest travels into your intestines.
The bigger contributor to flatulence is what happens in your large intestine. Your small intestine can’t fully break down every type of carbohydrate you eat. The leftovers pass into your colon, where trillions of bacteria feed on them and produce gas as a byproduct. The specific gases depend on your personal mix of gut bacteria. Some people’s bacteria produce more hydrogen, others more methane. A smaller subset of bacteria produce hydrogen sulfide, the compound responsible for the smell.
Anything that increases the amount of undigested material reaching your colon, or changes the bacterial population doing the fermenting, can increase how much gas you produce.
Foods That Produce the Most Gas
Certain carbohydrates are especially poorly absorbed in the small intestine, which means more fuel for gas-producing bacteria downstream. These are sometimes grouped under the acronym FODMAPs: short-chain carbohydrates found in a wide range of everyday foods. The most common culprits include:
- Beans and lentils, which contain complex sugars your body lacks the enzyme to break down
- Cruciferous vegetables like broccoli, cauliflower, cabbage, and Brussels sprouts
- Onions and garlic, high in a type of carbohydrate called fructans
- Whole grains, especially wheat and rye
- Fruits high in fructose, such as apples, pears, and watermelon
- Sugar alcohols (sorbitol, xylitol, mannitol), commonly found in sugar-free gum and candy
These foods aren’t unhealthy. In fact, many are excellent sources of fiber and nutrients. But if you’ve recently increased your intake of high-fiber foods, your gut bacteria may be producing significantly more gas than usual while adjusting. Johns Hopkins recommends working up to the recommended daily fiber target (25 to 30 grams for women, 30 to 38 grams for men) gradually rather than all at once. A sudden jump in fiber commonly causes gas, cramping, and bloating.
Food Intolerances
If certain foods consistently make you gassy, you may not be digesting them properly. Lactose intolerance is the most well-known example. People who don’t produce enough of the enzyme that breaks down milk sugar will pass that sugar intact into the colon, where bacteria ferment it and produce gas. Fructose malabsorption works the same way: unabsorbed fructose draws water into the intestine through osmotic effects and gets fermented by colonic bacteria, producing gas, bloating, and sometimes diarrhea.
These intolerances are dose-dependent. You might handle a splash of milk in your coffee but react to a large glass. Tracking which foods precede your worst episodes can help you identify patterns before pursuing formal testing.
Swallowed Air
Not all gas is made in your gut. Swallowing excess air, a habit sometimes called aerophagia, pushes air into your digestive tract that eventually needs to exit. Common triggers include eating too fast, talking while eating, chewing gum, sucking on hard candy, drinking through straws, and consuming carbonated beverages. Smoking also increases air swallowing.
Gas from swallowed air tends to be odorless, since it’s mostly nitrogen and oxygen rather than the sulfur compounds produced by bacteria. If your flatulence is frequent but doesn’t smell, swallowed air is a likely contributor.
Medications and Supplements
Several common medications cause gas as a side effect. Fiber supplements and bulking agents are frequent offenders, especially when started at full dose. Antacids, iron pills, multivitamins, opioid pain medications, and even some anti-diarrheal drugs can increase gas and bloating. If your flatulence increased after starting a new medication, that connection is worth exploring with whoever prescribed it.
Bacterial Overgrowth in the Small Intestine
Your small intestine normally hosts relatively few bacteria compared to your colon. When bacteria overpopulate the small intestine, a condition known as SIBO, they start fermenting carbohydrates before they can be properly absorbed. More bacteria means more gas, and that gas gets produced higher up in the digestive tract, which often causes uncomfortable bloating alongside excessive flatulence.
SIBO can develop after abdominal surgery, as a result of slow intestinal motility, or alongside conditions like diabetes or Crohn’s disease that alter gut function. Testing is straightforward: a breath test measures hydrogen and methane levels after you drink a sugar solution. Elevated levels indicate an overabundance of gas-producing bacteria. Treatment typically involves a course of targeted antibiotics and dietary adjustments.
Digestive Conditions Worth Ruling Out
Excessive gas is one symptom of several chronic digestive disorders. Celiac disease, an autoimmune reaction to gluten, damages the lining of the small intestine and impairs nutrient absorption. Gas, bloating, and diarrhea are among its core digestive symptoms. Inflammatory bowel diseases like Crohn’s disease and ulcerative colitis can also increase gas production as part of broader intestinal inflammation.
Irritable bowel syndrome (IBS) frequently involves excessive gas, though the underlying mechanism varies from person to person. Some people with IBS have heightened sensitivity to normal amounts of gas, making average gas volumes feel painful and disruptive.
When Gas Signals Something Serious
On its own, excessive gas is rarely dangerous. But certain accompanying symptoms change the picture. If increased gas comes alongside unexplained weight loss, fever, bloody stools, or persistent abdominal pain, those combinations can point to conditions like celiac disease, Crohn’s disease, or ulcerative colitis that need diagnosis and treatment.
A sudden, lasting change in your gas patterns also deserves attention if you haven’t changed your diet or medications. Your gut flora and digestive function are relatively stable day to day, so a persistent shift without an obvious cause is your body flagging that something has changed internally.
Practical Ways to Reduce Gas
Start with the simplest explanations first. Keep a food diary for a week or two, noting what you ate before your worst episodes. Patterns tend to emerge quickly. Common first steps include cutting back on carbonated drinks, slowing down at meals, and reducing gum chewing.
If high-fiber foods seem to be the trigger, don’t eliminate them permanently. Instead, reduce your intake temporarily and then reintroduce fiber slowly, increasing by a few grams every few days rather than jumping to a high-fiber diet overnight. Your gut bacteria adapt over time, and gradual increases produce far less gas than sudden ones.
For suspected lactose or fructose intolerance, try eliminating the suspected food for two to three weeks and then reintroducing it. A clear return of symptoms confirms the connection. Over-the-counter lactase enzyme supplements taken with dairy can also help if you’d rather not cut it out entirely.
If dietary changes don’t make a meaningful difference after a few weeks, or if you have any of the red flag symptoms described above, that’s the point where testing for conditions like SIBO, celiac disease, or other digestive disorders becomes the logical next step.