To control excess gas, beer intake should also be reduced or eliminated. These undigestible carbohydrates then serve as substrates for bacterial fermentation, yielding gas as a by-product. Sugar-free foods often contain sorbitol , manitol, or fructose, which are both poorly absorbed in the small intestine. This poor absorption leads to gas. Reducing intake of sugar-free foods may help prevent gaseousness.
Milk products contain lactose.
When a person lacks intestinal lactase, undigested lactose passes into the colon, where bacterial fermentation occurs. Several troubling symptoms result, one of which is excess flatulence. Lactase deficiency might be suspected when flatulence is accompanied by diarrhea, stomach rumbling, abdominal pain, and abdominal bloating, all occurring within several hours after lactose ingestion.