Passing gas up to 20 or 25 times a day is normal, so a noticeable increase usually means something has shifted in your diet, hormones, gut bacteria, or daily habits. For women specifically, hormonal fluctuations throughout the menstrual cycle, during perimenopause, or on new birth control can directly change how your digestive system processes food. The good news is that most causes of increased gas are manageable once you identify what changed.
Hormonal Shifts and Your Gut
Estrogen and progesterone don’t just regulate your cycle. They also influence how quickly food moves through your intestines and how diverse your gut bacteria remain. Progesterone, which rises in the second half of your menstrual cycle (the two weeks before your period), relaxes smooth muscle throughout your body, including your intestinal walls. This slows digestion, giving gut bacteria more time to ferment food and produce gas. That’s why bloating and flatulence often spike in the days leading up to your period.
During perimenopause, which can begin in your early 40s, estrogen levels fluctuate unpredictably before eventually declining. Estrogen helps maintain microbial diversity in the gut, and as levels drop, that diversity shrinks. Lower microbial diversity is linked to increased bloating, slower digestion, and reduced nutrient absorption. If you’re in your late 30s or 40s and noticing more gas after meals alongside irregular periods, hot flashes, or sleep changes, perimenopause could be the connection.
Starting or switching hormonal birth control can produce a similar effect. Any medication that alters your estrogen or progesterone levels can temporarily change your digestive patterns until your body adjusts, typically over a few weeks to a couple of months.
Foods That Ferment Quickly
If your diet has changed recently, even in small ways, that’s the most likely explanation. Certain carbohydrates are harder for your small intestine to break down, so they pass into the large intestine where bacteria ferment them and produce gas. These fermentable carbohydrates fall into a few categories:
- Prebiotic plant fibers: onions, garlic, beans, lentils, and many wheat products. These are healthy foods that feed beneficial gut bacteria, but they generate a lot of gas in the process.
- Lactose: the sugar in dairy. If you’ve added more milk, ice cream, or soft cheese to your diet, or if your lactose tolerance has decreased with age (which is common), this alone can explain a dramatic increase in gas.
- Fructose: the sugar in fruit, honey, and high-fructose corn syrup. Eating more fruit, switching to a sweetened drink, or adding honey to your tea can all tip the balance.
- Sugar alcohols: artificial sweeteners like sorbitol, mannitol, and xylitol found in sugar-free gum, mints, protein bars, and “diet” snacks. These are poorly absorbed and ferment rapidly.
You don’t need to eliminate all of these. The point is to notice whether something changed. Did you start eating more salads with onion and garlic dressing? Switch to a protein bar with sugar alcohols? Add a daily smoothie with extra fruit? Even a “healthier” diet can produce more gas simply because it contains more fiber and fermentable carbohydrates than your gut is used to. Increasing fiber gradually, over a couple of weeks, gives your gut bacteria time to adapt.
Swallowed Air Adds Up
About half of intestinal gas comes not from fermentation but from air you swallow. Certain everyday habits cause you to swallow significantly more air than normal: eating quickly, talking while eating, chewing gum, sucking on hard candy, using straws, and drinking carbonated beverages. Smoking also contributes.
Swallowed air typically produces more belching than flatulence, but excess air that isn’t burped up travels through the intestines and exits the other end. If you’ve picked up a new gum habit, started drinking sparkling water, or have been eating lunch at your desk while rushing through work, those small changes can meaningfully increase gas volume. Stress can also cause you to unconsciously gulp air, especially during anxious breathing.
Bacterial Overgrowth in the Small Intestine
When bacteria that normally live in the large intestine migrate into the small intestine and multiply there, the result is a condition called small intestinal bacterial overgrowth, or SIBO. These misplaced bacteria ferment food earlier in the digestive process than they should, producing excess gas, bloating, abdominal cramps, and a persistent feeling of fullness. Diarrhea is the most common bowel change, though some people experience constipation instead.
SIBO prevalence estimates range from about 2.5% to 22% of the general population, with female sex and increasing age both recognized as risk factors. It’s also more common in people with irritable bowel syndrome or celiac disease. SIBO is diagnosed with a breath test that measures gases produced by bacterial fermentation. If your gas is persistent, came on without an obvious dietary change, and is accompanied by diarrhea or significant bloating, it’s worth asking about testing.
IBS and Stress
Irritable bowel syndrome affects roughly twice as many women as men, and gas is one of its hallmark symptoms alongside abdominal cramping that worsens after eating, bloating, and alternating constipation and diarrhea. IBS symptoms tend to flare during periods of stress, poor sleep, or hormonal changes, which is why many women notice their symptoms worsen premenstrually.
Stress on its own can increase gas even without IBS. When your body is in a stress response, digestion slows because blood flow is redirected away from the gut. Food sits longer in the intestines, bacteria ferment it more thoroughly, and the result is more gas. If a stressful life period coincides with your increased gassiness, that connection is worth considering.
Endometriosis and Bowel Symptoms
Endometriosis, a condition where tissue similar to the uterine lining grows outside the uterus, can affect the bowels and mimic digestive problems. The key distinguishing feature is that endometriosis-related symptoms are cyclical: pain, bloating, and gas tend to worsen before menstruation and improve afterward. As the condition advances, symptoms can become more constant. Painful bowel movements, pain during sex, fatigue, and fertility issues are other signs. Many women with endometriosis are initially told they have IBS, and diagnosis can take years because the only definitive test requires a minor surgical procedure called laparoscopy.
Signs Something More Serious Is Happening
Most increased gas is harmless, but certain accompanying symptoms warrant a medical evaluation. Feeling full unusually early during meals, especially alongside nausea or unintentional weight loss, can signal a more serious digestive condition. Persistent bloating that doesn’t come and go but instead builds steadily over weeks deserves attention, particularly for women, as it can be an early sign of ovarian cancer.
Other red flags include bloody, black, or tarry stools, persistent diarrhea or constipation that lasts more than a few weeks, and abdominal pain that doesn’t resolve. These could point to inflammatory bowel disease, infection, or other conditions that need diagnosis and treatment.
Practical Steps to Reduce Gas
Start by looking at what changed. Review any dietary shifts over the past few weeks: new foods, supplements, protein powders, sugar-free products, or increased fiber. Track your symptoms alongside your menstrual cycle for one to two months to see if there’s a hormonal pattern. Cut back on carbonated drinks and gum temporarily to rule out swallowed air as a contributor.
If you suspect a specific food group, try eliminating it for two to three weeks and then reintroducing it. Dairy is the easiest to test because you can remove it cleanly. For broader food sensitivity, a low-FODMAP approach, which temporarily reduces all the fermentable carbohydrate categories, can help identify your triggers. This works best with guidance from a dietitian since it’s meant to be a short-term elimination diet, not a permanent restriction.
Over-the-counter options like simethicone (the active ingredient in most gas-relief products) can help break up gas bubbles and provide comfort, though they don’t address the underlying cause. Lactase supplements taken before dairy can help if lactose is your trigger. Walking after meals, even for 10 to 15 minutes, stimulates gut motility and helps move gas through more efficiently.