Board Thread:Random Talk/@comment-24224475-20141225004450/@comment-25940042-20141225215305

Intestinal gas is a mixture of swallowed air (if you don't belch it up, it'll pass through to the other end) and products of fermentation of bacteria. When sugars and starches that the human body can't digest enter the lower intestines, bacteria break them down. The byproduct of this system is a variety of gasses, including carbon dioxide, methane, and hydrogen sulfide. Methane is flammable and is produced by most (but not all) people (which is why some people can light their farts and some can't). Carbon dioxide is odorless and heavier-than-air. Hydrogen sulfide creates the majority of the fart smell. It is generally described as having a "rotten egg" stench.

Every person has a slightly different collection of bacteria and yeasts in their gut, and each organism contributes a slightly different nuance to the overall fragrance and volume of gas. Just as a fine wine keeps the palate stimulated with a variety of taste "notes," each person's unique batch of intestinal organisms lends shading to the stench of their farts. Your roommate (and my brother, apparently) simply have a collection of organisms that produce a horrid, malodorous, voluminous reek.

Is there anything that can be done for rotten bowel gas? Some people think that probiotic agents (foods and supplements containing "good" bacteria) help establish a less stinky colony in the bowel. I have yet to find a good study in the medical literature that confirms this, but it probably would do no harm. You can start with live cultured yogurt and step up to the more expensive capsules of freeze-dried bacteria if needed.

In 1997, Chester Weimer was granted patent No. 5593398 entitled "Protective underwear with malodorous flatus filter." The undergarment has a pocket on the rear that has a replaceable activated charcoal packet, which the subject farts through. The sound and odor are muffled by passage through the filter. I'd suggest buying a pair for your roommate and see if they work. If they do, you'll be living in a more fart-free environment. If they don't you will have a hilarious story to tell your friends. Either way it's win-win for you.