Do you fart? . Flatulence, commonly referred to as 'farting', is caused by gas in the bowel .It is a very normal bodily function, but when it becomes excessive and smelly, it can become embarrassing. Most gas passed during flatulence goes unnoticed because there isn't a smell. It may contain odorless gases, such as nitrogen, oxygen, hydrogen, carbon dioxide and methane, but a small portion includes hydrogen sulfide, which causes it to smell very bad. . Follow me @karthikmayur for more such tips!