Passing gas is a natural bodily process. The body produces it as part of digestion, but it can also come from air that people swallow when they are eating or drinking.

One controlled study found that individuals passed between 476 to 1491 millilitres of gas per day [1].

Approximately 7% of people report being bothered by the amount of flatulence they experience per day, while 11% mention experiencing uncomfortable side effects of excess gas, such as bloating.

But how do you know if you’re passing too much gas per day, and what could be the cause behind it? We investigate below!

The amount of gas expelled by a person daily is variable, but as mentioned above, studies have found that it’s somewhere between 476 and 1,491 millilitres per day. This gets expelled from the body as approximately 10 to 20 episodes of flatus daily [2].

Generally speaking, having upwards of 20 gas episodes per day isn’t necessarily a cause for concern on its own. However, if you experience any of the following in conjunction with passing a higher amount of gas, it would be worthwhile checking in with a doctor for any underlying cause:

• Abdominal pain

• Vomiting

• Diarrhoea or constipation

• Noticing blood in stool or vomit

• Unintended weight loss

So, the average person has up to 20 episodes of flatulence per day - but before you go reaching for the air freshener, did you know that the majority of gas that humans expel is actually odourless?

There’s one main compound that contributes to smelly flatus, too, and that is sulphur.

Sulphur compounds in gas, notably hydrogen sulphide (also called rotten egg gas - you can guess why!), accumulate as a by-product of digestion as the bacteria in our gut and intestines break down our food into waste (faecal matter). Eating foods high in sulphur content can worsen the smell of your gas, as it means your gut produces more hydrogen sulphide.

So in short, having smelly gas on occasion is normal and usually related to the foods you’re consuming. Smelly gas can also occur if you’re taking certain medications, like antibiotics for example, or if there is faecal matter in the rectum at the time of flatus.

If you find that your gas is always foul-smelling, it can sometimes indicate:

• An imbalance of gut bacteria

• Food intolerance such as lactose intolerance

• Coeliac disease

• An Inflammatory Bowel Disease (IBD) such as Crohn’s Disease or Ulcerative Colitis

Excessive gas, whether smelly or not, can be caused by a variety of things such as those listed below - some of which might surprise you:

Swallowed Air:

When we say swallowed air, we mean swallowing the gas inside food or taking in air while ingesting food. It’s estimated that drinking a glass of water can deposit double the amount of air into the stomach [4], which is expelled either through the mouth as a burp or as a flatus.  

The position you’re in while eating also affects how much air is swallowed while ingesting food. For example, if you’re in a reclined or laid-back position while eating, you’ll swallow more air than if you’re sitting up. You’re also more likely to then expel that air as flatulence, as the position the oesophagus is in while lying down doesn’t allow the excess air to exit [5].

You can also try to limit consumption of carbonated beverages like flavoured sodas or sparkling water, as they contribute to an increase in swallowed air.

Dietary Factors:

As we mentioned before, the foods you consume have an impact on how much gas is produced during digestion, and some foods can cause an increase in gas production during breakdown. These foods include:

• Beans and legumes

• High-fibre foods like wholegrains, prunes, cauliflower, broccoli, asparagus

• Allium vegetables such as onions and garlic

While you shouldn’t stop eating these foods as they carry essential nutritious benefits, you can try keeping a food diary to identify which foods may be causing an increase in gas and then look to limit them.

Food Intolerance:

If you’re intolerant to certain foods, eating them usually causes some upset in your digestive tract, which can lead to an increase in gas, as well as diarrhoea, abdominal cramps or bloating.

For example, those with lactose intolerance are unable to fully digest the sugar (lactose) within dairy, so it sits in the digestive tract being broken down by our gut bacteria through a process called fermentation, which creates gas as a by-product [6].

While there are no official tests to diagnose food intolerances, you might choose to keep a food diary to assist in identifying any problem foods or see an accredited dietician for expert advice.

Digestive Disorders:

Multiple digestive disorders can come with the side effects of excessive gas, including Coeliac Disease, Irritable Bowel Syndrome (IBS), Crohn’s Disease or Ulcerative Colitis.

Usually, though, these conditions have other signs or symptoms associated with them, including:

• Abdominal pain, bloating and cramping

• Diarrhoea, constipation or alternating between the two

• Mucus or blood in stool

• Fatigue and/or nutrient deficiencies

If you experience the above symptoms in conjunction with excessive gas, particularly if you’ve been experiencing them for a longer period, we recommend seeing your doctor for appropriate diagnosis and treatment.

Faecal Incontinence:

When we think of faecal incontinence, we may think it only means the involuntary release or leakage of stool, however, it also includes the involuntary release of flatus [7].

As individuals with bowel incontinence are unable to control the anal sphincter, and therefore bowel movements, those with the condition may also experience the inability to control passing wind.

We hope this article has helped explain what is considered abnormal or excessive when it comes to passing gas, and what can cause it.

If excessive flatulence is something you experience as part of having incontinence, our range of Dailee pull-ups and slips are a reliable solution with high absorbency.

They’re also equipped with active odour-locking materials that work for up to 12 hours at a time, so you can have peace of mind knowing that any unwanted odours stay neutralised.