Q: Why do I have to pass gas after I eat? My mother says it's
because I don't drink enough water. Is she right?
A: Water is certainly good for you and most children should drink more of it, but as far as we know, it's not a gas buster.
Your food contains many chemically complex substances. The human intestine is like a fancy laboratory that can handle some of these substances by breaking them down and shipping them across the wall of the intestine for use by the body. Some of the substances, certain sugars and starches, for example, are resistant to the body's laboratory and pass through it. Intestinal bacteria can "digest" some of these rejected substances. When they do so "gas" (really several gases including hydrogen and smelly methane) are a by-product of their chemical reactions. The gas produced by these bacteria becomes part of digestive waste and must pass out of the intestine just as bowel movement must. Some foods -- mostly those known as good sources of fiber -- have a lot of gas-producing substances. Your mother will want you to keep eating these foods because they are very healthy. The trick for you to learn is to let the gas out discreetly. Everyone passes gas, some just do it more obviously
Dr. Wilson is director of general pediatrics at the Johns Hopkins Children's Center; Dr. Joffe is director of adolescent medicine.