What Is Gas?
Gas is a normal result of your body digesting the foods you eat or beverages you drink. As your digestive system does its thing, gas forms as a side effect. You may also get gas from swallowing air.
Usually, you get rid of gas through your mouth (burping) or through your anus (flatulence). People pass gas one way or another about 20-30 times a day. It’s an ordinary occurrence, but you might find it uncomfortable or embarrassing.
Flatulence
This is when gas (called flatus) in your digestive tract passes through your rectum and anus, the opening where poop comes out of your body.
Other words used to refer to flatulence include:
- Farting
- Passing gas
- Intestinal gas
Belching
This is when gas comes up from your stomach and out of your mouth. Burping is another word for belching.
Where Does Gas Come From in the Body?
Your body usually makes gas in the digestive tract two ways: when you swallow air, and when the bacteria in your large intestine help digest your food.
Undigested food moves from the small intestine to the large intestine. Once it gets there, the bacteria go to work, making hydrogen, carbon dioxide, and methane, which then leave your body as gas. Some foods cause more gas than others.
You also swallow air when you eat and drink. This brings gasses like nitrogen and oxygen into the body. You usually burp up swallowed air. Whatever isn't released by burping goes into the small or large intestine, where it comes out as flatulence.
Gas and Flatulence Symptoms
Everyone burps and farts from time to time, especially while you eat or shortly after a meal. While symptoms vary, there are some common things you can expect if you get gas in your digestive tract.
In general, common gas symptoms include:
- Burping
- A feeling of fullness (bloating)
- Visible belly swelling (distention)
- Belly pain or cramping
- Passing gas or farting
Common symptoms of flatulence are:
- Passing gas frequently
- Passing odorless or silent gas
- Loud or smelly farts
- Bloating and discomfort
Why Am I So Gassy?
You may get more gas than usual from certain foods or drinks. Medical conditions can also lead to gas or gas symptoms in your digestive tract.
Foods that cause gas and flatulence
You’re most likely to get gas when you eat food with certain kinds of carbs. Gas forms when bacteria help you break down these undigested sugars, starches, and fibers.
Foods and drinks that commonly cause gas include:
- Beans
- Vegetables (especially broccoli, cabbage, and onions)
- Fruits
- Dairy products such as milk, ice cream, and yogurt
- Whole-grain foods such as whole wheat products
- Sugary drinks like fruit juice or soda
- Sports drinks or energy drinks, especially the kind with high-fructose corn syrup
- Gum, candy, or other products made with an “ol” sweetener (sorbitol, xylitol, erythritol, and mannitol)
Foods that cause gas tend to be high in FODMAPs. These are substances in carbs that are hard for your body to digest but that bacteria break down really fast. Many plant foods are high in FODMAPs. They're fiber-rich foods that are good for your health but that you may be sensitive to. A registered dietitian can tell you more about which ones might be the source of your gas and if the low-FODMAP diet might ease your symptoms.
You may also get gas when you drink something with carbon dioxide in it, such as seltzer water or soda. You burp the gas that makes the drink fizzy.
Medical conditions that cause gas and flatulence
You may get more gas or be more sensitive to it if you have certain health conditions, such as:
Celiac disease. You may get gas because your small intestine can’t digest gluten (a protein found in wheat) or you have trouble absorbing nutrients from food.
Gastroesophageal reflux disease (GERD). Also called acid reflux, GERD can cause you to burp a lot because you may swallow too much air. Acid that flows back into your throat or boosts gas production in your stomach can also make you burp.
Lactose or fructose intolerance. You may get more gas if you have problems digesting carbohydrates in food, especially the lactose found in dairy products or fructose found naturally in fruits or in products with high-fructose corn syrup.
Irritable bowel syndrome. IBS can cause problems with how gas or food moves through your gut. The lining of your intestines may also be more sensitive to normal amounts of gas (called visceral hypersensitivity).
Gastroparesis. This is when your stomach empties slower than normal. When this happens, you may get acid reflux, bloating, nausea, or other digestive symptoms.
Small intestinal bacterial overgrowth (SIBO). This is a condition where you have a large amount of bacteria in your small intestines that shouldn’t be there. These gut microbes can cause extra gas, along with diarrhea or weight loss.
Inflammatory bowel diseases. If you have Crohn’s disease or ulcerative colitis, you may get excess gas due to trouble digesting food or absorbing nutrients.
Colon, ovarian, or stomach cancers. You may get gas if a tumor blocks or presses on part of your digestive tract.
Many other conditions can cause excess gas or gas symptoms, including:
- Endometriosis
- Eating disorders
- Ovarian cysts
- Anything that blocks your bowels
- Constipation
- A hernia
- Splenic-flexure syndrome (a condition where kinks in your colon can trap gas)
Medications that cause gas and flatulence
Some drugs and supplements can affect the lining of your stomach or the speed in which food moves through your gut. You may get gas, bloating, or flatulence when you take:
- Antacids
- Diarrhea medication
- Opioid painkillers
- Fiber supplements
- Iron supplements
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Antifungal drugs
- Cholesterol-lowering drugs (statins)
- Certain laxatives
Talk to your doctor about all the medications you take, including vitamins. They’ll let you know what might trigger excess gas and how to avoid it.
Other things that cause gas and flatulence
Stress can affect how your brain and gut work together. Your digestion may slow, which can cause more gas and bloating. Psychological stress may also change your gut bacteria or worsen gas symptoms from other digestive disorders.
You may get more gas when you do things that make you swallow air, including when you:
- Eat or drink quickly
- Drink through a straw
- Chew gum or suck on a piece of candy
- Smoke
- Have loose dentures
Swallowed air may come out as flatulence if it passes from your stomach to your large intestine before you get the chance to burp it out.
How Are Gas-Related Illnesses Diagnosed?
Since diet is the main cause of gas, your doctor will want to know about the foods you eat and your symptoms. Keep a record of what you eat and drink to help identify foods that trigger gas symptoms. They may also ask you to notice how often you pass gas.
You may have to stop eating certain foods for a little while to pinpoint the ones that cause gas. For example, if your doctor thinks you have a lactose intolerance, they may ask you to cut out dairy to see if that helps ease your symptoms.
If bloating is a problem, your doctor may examine you to check for medical problems.
During a physical exam, your doctor may:
- Feel your belly for swelling
- Check for any masses
- Listen to your belly with a stethoscope
- Press on your belly to see if it hurts or feels tender
- Tap on your abdomen to see if it sounds hollow like a drum (a sign you have excess gas in your belly)
If you have chronic belching, your doctor will look for signs that you swallow a lot of air. If they think you do, they may get an X-ray of your GI tract – your esophagus, stomach, and upper small intestine – to rule out diseases that may cause your symptoms.
Other tests used to diagnose gas-related illnesses include:
Blood tests. These can check for signs of celiac disease or other health problems.
Breath test. You may drink a solution of sugar, carbohydrates, or carbon. Then your doctor will have you breathe into a tube every so often so they can check for gas-causing methane or carbon dioxide.
X-rays. This can check for physical problems that aren’t noticeable during a physical exam.
Stool tests. Your doctor may check your poop for signs of blood, abnormal bacteria, or signs of other digestive issues that cause gas, such as intestinal inflammation, pancreatic dysfunction, viruses, or parasites
Endoscopy. Your doctor puts a camera through your mouth and into your stomach to look at your upper intestines. They may take tissue samples from your gut to check for signs of inflammation or other conditions.
Colonoscopy. This test checks for signs of inflammatory bowel disease (IBD), tumors, ulcers, bleeding, or other problems in your large intestine (colon).
Gas and Flatulence Relief
Gas problems are treated by changing your diet and by training yourself to swallow less air. There are also prescription and over-the-counter medications that can help.
Changing your diet will mean getting rid of the foods that cause gas. Unfortunately, this may also result in you having fewer nutritious foods. Ask your doctor to help you build a diet that’s healthy but doesn't cause much gas.
Things you can do at home:
- Cut out gum or hard candy.
- Eat more slowly.
- Make sure any dentures you wear fit properly.
- Don't drink through straws.
- Keep a food diary and avoid the foods that cause gas.
- Eat smaller, more frequent meals.
- Chew your food well.
- Stay hydrated to avoid constipation.
- Eat probiotic-rich foods.
- Exercise regularly.
Over-the-counter medications include:
- Antacids, especially those that contain simethicone
- Probiotics, which are used to help stop the growth of bad bacteria and add good bacteria to your digestive tract
- Lactase supplements, which can help if you have lactose intolerance
- Beano, a product containing the enzyme that helps digest the sugars in beans and many other vegetables
Takeaways
Gas is a natural result of digestion or swallowing air. You may need to pass gas or burp many times a day. This usually isn’t a sign of a medical condition, even if you pass gas a lot or it smells bad.
Occasional gas usually isn’t something to worry about. But you should talk to your doctor about your symptoms if they’re uncomfortable or get in the way of your daily life.
You can lessen everyday gas with diet and lifestyle changes, along with over-the-counter medication. Tell your doctor if those don’t help enough. You may need to address a hidden health condition that affects your digestive tract.
What causes excessive flatulence?
It’s normal to pass gas many times a day. You may fart more often if you eat or drink things with sugars, starches, or fibers that your stomach can’t fully digest. Health conditions such as IBS, lactose or fructose intolerances, small intestinal bacterial overgrowth (SIBO), or other digestive disorders may also cause excess gas.
How can I reduce gas in my digestive system?
It depends on what’s causing your gas in the first place. You may lessen gas symptoms by eating or drinking less fiber, fructose, or lactose. Over-the-counter medications may also help. But you may need to address a hidden health condition, such as celiac disease, irritable bowels syndrome (IBS), or small intestinal bacterial overgrowth (SIBO).
Talk to your doctor before you make big changes to your diet or lifestyle.
What digestive problems cause gas?
Health conditions associated with excess gas include irritable bowel syndrome (IBS), small intestinal bacterial overgrowth (SIBO), food intolerances, celiac disease, among many others.
How does gas affect the digestive system?
Common gas symptoms include passing gas and burping. This is natural and harmless. But if you have a lot of gas, you may get feelings of fullness (bloating) or belly swelling (distention). Trapped gas can also be painful, but this isn’t dangerous.
Which organ is responsible for gas?
Usually, you get gas in your stomach and intestines. This happens when you swallow air or the bacteria in your large or small intestines break down food.
