I found this on good old wiki:
The noises commonly associated with flatulence are caused by the vibration of the anal sphincter, and occasionally by the closed buttocks. The sound varies depending on the tightness of the sphincter muscle and velocity of the gas being propelled, as well as other factors such as water and body fat. The auditory pitch (sound) of the flatulence outburst can also be affected by the anal embouchure. Among humans, flatulence occasionally happens accidentally, such as incidentally to coughing or sneezing or during orgasm; on other occasions, flatulence can be voluntarily elicited by tensing the rectum or "bearing down" and subsequently releasing the anal sphincter, resulting in the expulsion of a flatus.Flatus is brought to the rectum by the same process which causes feces to descend from the large intestine, and may cause a similar feeling of urgency and discomfort. Nerve endings in the rectum usually enable individuals to distinguish between flatus and feces, [6] although loose stool can confuse the individual, occasionally resulting in accidental defecation, or "sharting" or "farticle".

Flatulence - Wikipedia, the free encyclopedia

I'm a bloke and I find farting gross haha. It's just weird to think that your letting gases from inside of you where your organs are and that out of a whole that is also the same whole you s**it out of...and then it goes in peoples' mouths!!! No....farting is definately not for me. In fact I dont fart, I've just decided. I DO NOT NEED TO FART EVERYONE.

i fart alone never around anyone well i try not to.
did you no its healthier to fart on a baby than breath in its face? :]

where the hell did you find that fact? lol :shocked:

around some people we hide it...around some people we dont. its as simple as that.

sounds fair lol.

Apparently it's true!! But I think its kissing a baby instead of breathing on it due to the germs that are in the mouth.