By Alexander McNamara

Published: Sunday, 13 February 2022 at 12:00 am


Everybody burps and farts around 2.5 litres of gas per day, which comes from the air we breathe, the drinks we quaff and the bacteria in our digestive system. Our bodies get rid of this excess gas via the mouth and anus. You may not even notice yourself passing gas – it can be very small quantities, and sometimes doesn’t smell at all.

Unlike in cows, methane is not a major constituent of our farts. So if someone sets a fart alight, it’s usually hydrogen gas that’s burning.

While farting is completely normal, if you start to fart more than normal, if can be the result of an underlying medical condition.

Why do we fart?

A small amount of swallowed air makes it into the intestines, but most of the gas there is produced by the bacteria that help to digest our food. This gas needs to come out, so it is expelled by burping and farting.

The gas is mainly hydrogen and carbon dioxide. The smell comes from sulphur compounds that are only present in trace amounts.

The nerve endings in your anus allow you to distinguish between a build-up of gas and a solid stool, so you can pass wind safely.

Why do I fart so much?

It’s normal for some people to fart more than others. According to the NHS, the average person farts between 5 and 15 times a day. However, there are a few conditions that can cause you to fart more than normal.

Farting is a symptom of both coeliac disease and lactose intolerance. As well as eating foods that are difficult for you to digest, excessive flatulence can be caused by constipation, irritable bowel syndrome, indigestion and gastroenteritis. It can also be a side effect of some medications.

If you’re concerned about your farting, visit your GP.

If you hold in a fart, where does it go?

"Holding
What happens if you hold in a fart? © Getty Images

It stays right there! If you suppress a fart, it actually just seeps out more quietly, or you might be able to hang on until the next time you are on the toilet. But sooner or later, that fart is coming out! – Luis Villazon

What foods make you fart?

Beans, beans, they’re good for your heart. The more you eat, the more you fart… or so the poem says. But why do beans make you fart, exactly?

Beans, like many other foods, contain plenty of soluble fibre. While this is great for your health, it can also make you fart – soluble fibres are fermented in the colon, rather than being digested in the intestines. This produces gas, which becomes a fart.

Other fart-inducing foods include pulses, such as lentils and peas, brassicas including cabbages and broccoli, onions, prunes and apples.

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