Flatulence (or passing wind, or farting) is when excess gas produced during digestion is released from your bottom (anus).
Most people experience flatulence, but if it happens too often it can be a sign of an underlying health condition, like irritable bowel syndrome (IBS) or coeliac disease.
In many cases, flatulence occurs as a result of eating certain foods, and a change in your diet and lifestyle could help to control it.
Which foods and drinks are most likely to cause gas?
The foods most likely to cause excess gas in your body are ones that contain sugars, carbohydrates or fibre that can’t be broken down in your small intestine. This causes them to move along into your colon.
The colon contains a lot of bacteria that then break down these products and create gas in the process.
Here are some common foods that cause the bacteria in your colon to become active and produce excess gas.
High FODMAP vegetables
Some vegetables, such as onion, garlic, cauliflower, leek and artichoke, contain carbohydrates that the body finds harder to absorb.
These carbohydrates -- known as fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) -- can’t be broken down in the small intestine and so they move into the colon.
If you think these vegetables may be causing your excess gas, you can always try reducing how much of them you eat. You could also include more of the vegetables that are low in these carbohydrates, such as carrots, spinach, potatoes and lettuce in your diet.
But always see a doctor before making any drastic changes to your diet.
Foods and drink high in fructose
Fructose is a sugar that’s naturally present in fruit and some vegetables, such as watermelon, grapes, apples, peas and asparagus.
If you have a digestive disorder called fructose malabsorption, your body may find it harder to absorb the fructose in these foods. This means that foods containing fructose may make it into your colon.
Fruit juice can also have the same effect in some people.
Foods high in fibre
Some foods, like fruit, oats, beans and lentils (pulses), are high in fibre.
Fibre is a carbohydrate that isn’t easily digested in the small intestine, so it may reach the colon undigested.
If you’re trying to reduce flatulence, you could try limiting your intake of foods containing fibre. However, you should check with a doctor before making any major changes to your diet.
Foods high in raffinose
Beans and Brussels sprouts also contain the complex sugar raffinose -- a type of carbohydrate that is hard to digest in the small intestine. This means it has to be digested by the bacteria in the colon.
Lower levels of raffinose can be found in vegetables like cabbage and asparagus.
All milk and dairy products, including yoghurt and cheese, contain the natural sugar lactose which can cause problems.
Some people have lower than average levels of lactase, the enzyme that digests lactose. If lactose isn’t broken down in the small intestine it passes to the large intestine where bacteria break it down, causing gas.
This can cause symptoms related to lactose intolerance.
Some people who have lactose intolerance find it easier to digest yoghurt than milk. This is because yoghurt contains live bacteria, which help to break down lactose during digestion, relieving lactose intolerance symptoms.
Cutting out foods safely
To reduce the amount of gas your body produces, you shouldn’t avoid these foods altogether as it’s not safe to cut certain foods from your diet without speaking to a doctor or dietitian first.
Instead, monitor to see how your body reacts to reducing these foods 1 by 1 and discuss any changes with a doctor.
What else can I do to reduce flatulence?
As well as limiting certain foods, you can also try:
- getting regular exercise -- this can aid digestion
- eating and drinking more slowly -- to prevent the build-up of gas
- eating smaller meals more frequently
Speak to a pharmacist or doctor for further guidance on how to safely get and use medicines to help with your flatulence.
When to see a doctor for flatulence
If you’re regularly passing excess gas and it’s become a problem for you, see a doctor.
You should get checked by a doctor if you have flatulence and have:
- constant or recurrent tummy pain and bloating
- blood in your poo
- muscle or joint pain
- a high temperature (fever) or feel cold
- lost weight without trying to
- repeated bouts of diarrhoea or constipation
- a sudden need to pass poo (bowel incontinence)
If making changes to your diet doesn’t have much effect, explore the other causes of flatulence to see if any of these may apply to you.