Milk

In addition to the foods you eat, the milk you drink may contribute to excessive gas. In many people, the body's production of the enzyme that digests lactose, or milk sugar, begins to decrease in childhood. Bacteria in the large intestine convert any undigested lactose into hydrogen, resulting in bloating, cramps and gas.

To test whether lactose intolerance is causing your discomfort, you can eliminate milk for a week or two and see if you get relief. But even if you prove to be lactose-intolerant, you don't have to do without milk's abundance of calcium, protein and vitamins.

Since most lactose-intolerant people can digest at least some milk, try limiting your intake to a half-cup at a time for a total of two or three cups a day. If you still experience gas problems, here are some suggestions:

• Drink lactose-reduced milk, available in most grocery stores.
• Use over-the-counter drops or tablets that make milk easier to digest.
• Switch to dairy products such as cheese and yogurt, which contain less lactose than milk does.