Increased Gas

The production of the gases hydrogen, methane, and carbon dioxide rises as a result of lactose fermentation in the colon. In fact, the colon microflora becomes quite efficient at fermenting lactose into acids and gases in people with lactose intolerance. This causes the colon to ferment more lactose, which increases flatulence even more.

Because of differences in the efficiency of the microflora and the rate of gas reabsorption by the colon, the amount of gas generated might vary greatly from person to person. It's interesting to note that the gases produced by lactose fermentation are odorless. Actually, rather than carbs, the odor of flatulence is caused by the breakdown of proteins in the gut.