This is why you’re farting so much – and what makes them smell so bad.

Fourteen times a day – that’s the number of times we fart on average, but there’s a few reasons why we do it more than usual

It’s a bodily function we all perform, whether you find farting funny, disgusting, or like to pretend you never do it.

On average, we produce half a litre of fart gas a day – which is also referred to as passing wind, among other, less polite names.

If your bodily functions are all ticking along nicely, this fart gas spreads out over 14 daily farts.

But let’s be honest, there are times when it seems you are exceeding the daily average of farting. Why is this?

Dr Patricia Raymond, a physician and a fellow of the American College of Gastroenterology spoke to Refinery29 and explained why some days are gassier than others.

1. In-flight farting

Have you ever noticed how you’re a bit more liberal with the farts when you’re on an aeroplane?

There is a genuine reason behind this. Research has shown how high altitude causes the gas in our bodies to expand.

In turn, this leads to bloating and eventually flatulence. Bearing in mind how packed commercial flights can be, it’s enough to put anyone off getting on a plane ever again.

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2. Healthy eating

Not all the food we eat gets digested. Anything our small intestine doesn’t process gets passed on to our large intestine where it brews.

Unfortunately, we owe our smelliest farts to the healthiest foods.

Fruit, vegetables, whole-grains and legumes all generate a stink.

Onions, broccoli, cauliflower, cabbage, and sprouts contain a carbohydrate called raffinose, which the stomach and the small intestine are also unable to digest.

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3. Too much air

There are two ‘sources’ of our farts. One is the gas produced in our large intestine.

The other is the air we swallow, which makes its way through our digestive tract.

The good news is if you’re swallowing a lot of air, the farts which are a by-product tend to be odourless, rather than the silent-but-deadly variety.

It’s called ‘aerophagia’ and it’s caused by eating your meals quickly, chewing gum, or drinking lots of carbonated beverages.

4. Absorption

Now on to the silent-but-violent variety.

When farts are particularly unpleasant, it may be because our bodies are having trouble absorbing certain nutrients.

We all react differently to various food types, but the most common one people experience problems with are the sugars from carbohydrates followed by lactose.

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5. Something more serious

The quantity and ‘quality’ of our farts will differ from day to day.

But Dr Raymond suggests recurrent episodes, or gas and bloating that comes with pain or other symptoms like diarrhoea or constipation, are worth talking to your doctor.

Excessive and bad smelling farts could be symptoms of medical conditions such as IBS and celiac disease.