Search Result

Digestive system


The digestive system is one of nature’s marvels: an uninterrupted conveyor belt running 24/7 which release enzymes and hormones to extract the nutrients and goodness from the food we eat. What’s left is waste, which we get rid of as shit.


Gas is the air in the digestive system which leaves the body as burps or farts. Burping or belching come from the stomach which has a different chemical composition from a fart which has less atmospheric gas content (air) and more bacterial gas content.

Gas in the digestive system is usually produced by swallowing air, and the breakdown of foods by enzymes and bacteria in the gut (eg: processing undigested carbohydrates and proteins). These gases are primarily carbon dioxide, oxygen, nitrogen, and hydrogen; with smaller amounts of some methane and sulphur.

We have scoured the Internet and you can fart between a few times a day to 10, 20, 30, 40 times times, producing around .5 litre plus of gas, but opinions vary greatly.


Burping is generally caused by swallowing air when eating or drinking, or inhaling, and is usually a mixture of nitrogen and oxygen. Carbonated/ fizzy drinks (including beer) often make you burp (more) which is primarily carbon dioxide from the drink itself.


Out of idle curiosity searching on farting on YouTube yielded over 31 million results (some remarkably homophobic but that's not what the section is about). We all do it, we all hear them, and some of our 'friends' have turned it into an art form (Philip). And yet it can remain a surprisingly embarrassing topic, partly because people believe they fart more often than others (or maybe it's because others are better at concealing them).
What your farts say about your health | Seeker | 13 Apr 2016 | 3m 55s

Foods that can cause gas

  • Vegetables such as broccoli, Brussels sprouts, cabbage, cauliflower, artichokes and onions
  • Grains such as whole wheat, brown rice, barley, bulgur, corn bran and wheat bran
  • Legumes such beans and lentils
  • Fruits such as apples, peaches, pears, prunes and raisins
  • Fruit juice such as apple and pear and other drinks that contain high-fructose corn syrup, a sweetener made from corn
  • Milk and milk products including cheese, ice cream, and yogurt
  • Processed and packaged foods such as bread, cereal
  • Sugars such as table sugar, lactose (in dairy foods), maltose (found in grains), sugar alcohols (such as glycerin and maltitol syrup) used in energy bars, sugar-free sweets, and other processed foods
  • Sugar-free products containing sugar alcohols such as sorbitol, mannitol, and xylitol

Things to know

  • Sulphur rich foods (eg: broccoli, cauliflower, cabbage, kale, Brussels sprouts) can produce smelly farts while fruits, vegetables and beans usually don’t
  • Skatole and indole which occurs naturally in shit (before you poo it out) also add to the stench of farts
  • Farts can travel up to several metres/ feet per second and can be silent or noisy depending on the speed of the gas leaving the body, the position of the arse cheeks and tightness of the arsehole sphincter muscle
  • The more constipated you are (with food fermenting in your digestive system) the more you will fart and the smellier they will be
  • Depending on whether you are the type of guy who takes ownership you can (1) blame your farts on the dog even if there isn't one (Debrett's A-Z of Modern Manners); (2) blame the person who has just left the lift if you've farted and someone else has got in; (3) offer them a face mask; or (4) ask them if they can do better.

And ‘yes’ it is true: farts can be lighted but we don’t recommend it as you can burn yourself and singe hair!

Why are you farting? | BrainStuff: HowStuffWorks | 15 Jul 2014 | 4m 18s

Ways to reduce gas

  • Chew food slowly and thoroughly instead of gulping it down
  • Avoid straws which encourages air swallowing and drinking out of tins/ bottles with narrow openings
  • Reduce carbonated drinks; eg: soft drinks and beer; chewing gum, or sucking on sweets
  • Select/ de-select food types (while maintaining a healthy diet)
  • Avoid sugar-free products containing sugar alcohols such as sorbitol, mannitol, and xylitol
  • Reduce your lactose intake found in dairy products and older cheeses can contain lactose
  • Avoid smoking or chewing tobacco
  • Physical/ aerobic activity will speed up digestion and help eliminate gas
  • It may sound old fashioned but walking off a meal moves the air bubble to the upper stomach where you can burp
  • Loose fitting dentures trap air in saliva causing you to swallow more frequently... who would have thought?!
  • Nervous people can swallow excess air so relaxation may help

Fart | Wikipedia
Flatulence | NHS
Flatulence | Wikipedia
Could You Outrun A Fart? | AsapSCIENCE | 13 Apr 2016 | 3m 25s
Are Silent Farts Worse? | AsapSCIENCE | 14 Nov 2013 | 1m54s
Why Do We Like Our Own Farts? | AsapSCIENCE | 9 Nov 2014 | 2m 55s
Why Are You Farting? | BrainStuff: HowStuffWorks | 15 Jul 2014 | 4m 18s
Why Do We Burp and Fart (So Much)?! | SciShow | 24 Dec 2013 | 3m 22s
The Poop Cycle | AsapSCIENCE | 1 Aug 2013 | 3m 13s

↑ Back to top