What Your Farts Can Tell You About Your Gut Health

At some point in childhood, farts become one of two things: an embarrassing secret we pretend never happens, or the butt of every joke. As adults, most of us stop joking about them, but many still feel a twinge of shame about passing gas—especially when it’s frequent, loud or smelly. 

The good news? You’re one of the nearly 100% of people who pass gas. Not only is breaking wind totally normal, but paying attention to your gas patterns—including changes in odor, sensations, frequency and even sound—can give you insights into your health and clue you in to when your body is trying to tell you something is amiss. To help you understand what is “normal” and when your body is signaling a problem, we spoke with the experts. 

How They Smell

Ever wonder why some farts go undetected, while others make you wrinkle your nose and blame it on the dog? “Most gas is actually odorless, and smell comes from tiny amounts of sulphur-containing compounds produced during digestion,” says Shy Vishnumohan Ph.D., APD. 

As gut bacteria ferment the foods you eat, they release gas as a by-product. Its odor can range from barely there to pungent, depending on what you ate and the mix of bacteria in your digestive tract.

“Occasional changes in smell are normal, but persistent, unusual odors, especially when paired with bloating, constipation or diarrhea, may signal altered digestion or microbial imbalance,” says Ava Safir, J.D., M.S., RDN. Lingering, strong odors could be a sign of carbohydrate malabsorption, small intestinal bacterial overgrowth (SIBO) or another digestive issue that may need medical attention.,

The Sounds They Make

Unfortunately, we can’t always predict whether a fart will slip out silently or make its presence known. But whether they’re squeaking out or loud and proud, the noise your farts make has little to do with the health of your gut. “The sound of passing gas is mostly mechanical and depends on how much gas is present, how quickly it moves and the tone of the muscles it passes through,” says Safir. 

While you can’t consciously control the sound, certain anatomical factors can make farts louder and harder to manage. Safir explains that constipation, pelvic floor muscle tension and hemorrhoids can all affect rectal muscle tone, which may change how gas is released.

How Often You Fart

“Passing gas anywhere from a few times a day up to about 20 times daily is considered normal,” says Safir. But if some days you barely notice any gas, while others you can’t stop breaking wind, it’s most likely thanks to what you’ve eaten. “More frequent gas often tracks with more fermentable carbs, including beans/pulses, sugar alcohols, high-FODMAP foods or intolerances to lactose or fructose,” says Vishnumohan.

If you’re trying to increase your fiber intake, don’t worry—this extra gas is usually temporary. Most research shows that within two to six weeks of increasing fiber intake, most people’s flatulence frequency returns to normal. While an occasional post-bean or fiber-rich meal increase is normal, persistent gas accompanied by diarrhea and unintentional weight loss is a sign to visit your health care provider, Vishnumohan explains.  

How They Feel

How your belly feels before and after passing gas can reveal a lot about your digestive health. Slight discomfort before or during gas is usually normal, but pain shouldn’t be severe and linger. According to Safir, cramping, intense pain or the sensation of gas feeling “trapped” may signal slowed digestion, constipation, heightened gut sensitivity (also called visceral hypersensitivity) or trouble digesting certain carbohydrates.

When You Should Visit a Health Care Professional

Getting familiar with your gas and bowel patterns can help you identify potential digestive issues. While occasional changes are normal, experts say these are signs warrant a check-in with your health care provider:

• Blood in Your Stool. Seeing blood—whether bright red or dark and tarry—can indicate anything from hemorrhoids to inflammatory bowel disease, intestinal bleeding or even colon cancer. Any appearance of blood should be evaluated promptly.
• Symptoms That Keep Getting Worse. Occasional bouts of increased gas or cramping can result from stress, what you ate or how fast you ate it. But persistent or worsening symptoms may signal something more serious. “Gas, bloating or discomfort that lasts for weeks rather than days may indicate impaired digestion, slowed motility or difficulty absorbing certain foods,” says Safir. 
• Pain. “Passing gas should not regularly cause cramping or sharp abdominal pain,” says Safir. Pain may signal an imbalance, such as SIBO or a food intolerance, and should be evaluated by a health care provider.
• Unintended Weight Change or Loss of Appetite. “Weight loss without trying or feeling full after small amounts of food may signal that digestion or nutrient absorption is not working optimally,” says Safir. If this happens, it’s important to see your health care provider to rule out any underlying causes. 
• Unexplained Changes in Patterns. Changes in diet, movement, hydration and stress may lead to short-term changes in your digestion, including bowel frequency and gas patterns. However, if patterns shift and don’t return to normal despite consistent routines, it could signal an underlying issue that deserves medical attention.

Our Expert Take

Farting is a normal part of healthy digestion, even if it feels a little embarrassing at times. Everything from what you eat to how quickly food moves through your gut can affect how often you pass gas, what it smells like and even how it sounds. Most day-to-day changes are harmless, but persistent symptoms are worth paying attention to. Increased pain, worsening digestive issues or unexplained changes in appetite or weight are signs it’s time to check in with your doctor or health care provider.