屁是臭的这大家都知道，那屁为什么会臭呢？这要从屁的成分和我们吃的食物说起。

Ever pull someone's finger and hear a weird noise come out of his or her butt?

Ever sit in a tub of water and see bubbles come out of your hiney?

This strange noise and vibrating sensation that came from your butt is most likely caused by a fart.

A fart is a combination of gases (nitrogen, carbon dioxide, oxygen, methane, and hydrogen sulfide) that travels from a person's stomach to their anus. When a person swallows too much air or eats foods that the human digestive system cannot digest easily gas becomes trapped in his/her stomach. The only way for this excess gas to exit the body is through the anus.

The gas that makes your farts stink is the hydrogen sulfide gas. This gas contains sulfur which causes farts to have a smelly odor. The more sulfur rich your diet, the more your farts will stink. Some foods that cause really smelly farts include: beans, cabbage, cheese, soda, and eggs.

A scientific name for a fart is flatus or flatulence.

The word fart is just one of many different terms used to describe the release of gases from the human body. Other popular names for farts or farting include: gassers, stinkers, air biscuits, bombers, barking spiders, rotten eggs, and wet ones. You can pass gas, break wind, blast, beef, poof, rip one, let one fly, step on a duck, and cut the cheese.

Farts can be stinky, wet, loud, or silent but deadly. Pee-eeew!!!

Did you know?
On the average, a healthy person farts 16 times a day.
Hey guys, don't be fooled by girls who tell you that they never fart. Everyone farts, including girls. In fact, females fart just as much as males.
Many animals fart too. Cats, dogs, and cows. Elephants fart the most.
People fart the most in their sleep.
Farts that contain a large amount of methane & hydrogen can be flammable.

nitrogen: 氮

methane: 甲烷

hydrogen sulfide: 氢硫化物

anus: 肛门

（英语点津 Annabel 编辑）