Wonder what causes gas? It occurs when a food does not break down completely in the stomach and small intestine. As a result, the food makes it into the large intestine in an undigested state. For example, if you are "lactose intolerant," it means that you lack an enzyme (lactase) in your intestine -- the enzyme that breaks lactose apart into two sugar molecules so they can enter the bloodstream. Without lactase, lactose passes undigested through the stomach and small intestine and arrives in the large intestine. There, the lactose meets up with billions of hungry bacteria -- the natural "intestinal fauna" we all have in our large intestine. These bacteria are happy to digest lactose. They produce a variety of gases, in much the way that yeast produces carbon dioxide to leaven bread. Gases such as methane, hydrogen and hydrogen sulfide are common gases that these bacteria produce. Hydrogen sulfide is the source of the odor we associate with flatulence.

by Anonymous 13 years ago

I don't think anyone was really wondering what causes gas, and now I know no one is wondering.

by Anonymous 13 years ago

Another scientist! Vonderful

by Anonymous 13 years ago

*quiet sorry couldn't resist

by Anonymous 13 years ago

Oh shit, thank you for pointing that out! Haha

by Anonymous 13 years ago