The noises commonly associated with flatulence are caused by the vibration of the anal sphincter, and not by the 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, farting sometimes happens accidentally, such as incidentally to coughing or sneezing; on other occasions, farting can be voluntarily elicited by tensing the rectum or "bearing down" and subsequently releasing the anal sphincter. Humans are also known to flatulate during sleep, largely due to the relaxed state of body muscles, which results in the average person flatulating about 10-20 times through any given night.[citation needed]

Flatus is brought to the rectum via peristalsis, which also 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, although loose stool can confuse the individual, occasionally resulting in accidental defecation.

http://en.wikipedia.org/wiki/Flatulence

10/20/2007 1:59:26 AM

haha i got to sphincter and busted a lol

10/20/2007 2:00:46 AM

Quote :

"although loose stool can confuse the individual, occasionally resulting in accidental defecation."

10/20/2007 2:01:19 AM

I call bullshit, maybe I'm odd, I KNOW when my buttcheeks are a flappin and a fartin. Hell the silent farts, you tilt sideways in your seat to pull your buttcheeks apart so it just becomes laminar flow.

10/20/2007 2:19:48 AM