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Nearly everyone has been in a situation where passing gas would be embarrassing. Choosing to “hold in” or delay flatulence from escaping is often the polite thing to do. But holding in a fart for too long isn’t good for your body.

If you decide not to release a fart, some of the gas will be reabsorbed into the circulatory system. From there, it goes to the lungs for a gas exchange throughout the pulmonary circulation system and is expelled through breathing.

While this isn’t a “mouth fart,” per se, it’s the gas from the fart coming out of your mouth.

So how often does this really happen? And can holding in flatulence all the time hurt your body in the long run? Let’s cover all of that and more.

Farts, also called flatus, are a natural part of your digestive process. Bacteria in your intestines create gases as they break down and metabolize the food that you eat. These gases expand your colon, giving you a feeling of fullness and discomfort. The gas needs a place to escape, and usually, it’s through your rectum.

When you block a fart from escaping, some of the gas can pass through your gut wall and be reabsorbed into your bloodstream. From there, it can end up being exhaled through your lungs, coming out of your mouth via exhaling.

You won’t be able to taste a fart that escapes through your mouth.

Flatulence is made up of swallowed air and gas produced by bacteria in the colon from undigested carbohydrates. It smells bad due to the breakdown of various foods into certain gases, primarily sulfur-containing gases. These aren’t reabsorbed by your body.

Gas escaping through your mouth isn’t the only possible side effect if you try to hold flatulence in.

Bloating and belching

Swelling and bloating in your abdomen can be caused when you’re gassy and deny that gas an exit. A bloated belly can make you more prone to belching.

Pain and swelling

When you have a lot of gas, you may feel uncomfortable. But trapping the gas in your body by holding in a fart can take that discomfort to the next level. Cramping and pain can occur from holding in flatulence.


If you regularly hold in flatus, it’s possible that air pockets will begin to form inside of your digestive tract. If these pockets become infected or inflamed, you can develop the digestive condition diverticulitis.

If gas that is a part of flatulence is making its way out of your mouth, anyway, does that mean it’s OK to fart into someone else’s mouth?

Well, it’s not proper custom unless you’re a young child, but it won’t cause pinkeye, spread a virus or cause giardia, an infection of the digestive tract that’s caused by a parasite.

All three of those are commonly spread myths.

It has no medical side effects because flatus only contains gas. There shouldn’t be any fecal particles in it. The spread of fecal particles is necessary to cause any of the conditions above.

Holding in your flatulence can feel necessary out of common courtesy, but don’t make it a habit when you don’t have to hold it in. Gas from your intestines will get out one way or another, even if it has to travel back into your bloodstream and escape through your mouth.