Everyday, everyone passes wind through their anus. It is very natural for a person to fart. Contrary to what many people might believe, there's no proof that men fart more often than women do. In fact, a study published in the British medical journal showed that men and women produced an equivalent volume of flatus per day when placed on a similar diet.
The average person farts about 15 times a day, releasing about half a litre of gas into the environment. The gas released could be relatively odourless or foul smelling, depending on the person's diet. Swallowed air can give off odourless farts while sulphur-containing foods can cause foul smelling farts.