DEAR DR. DONOHUE: I hope you can answer our problem and that my husband will read it. My husband has a problem with flatulence. I would venture to guess that he passes gas every 15-20 minutes all day long. The odor could knock you out. He is extremely fit, and we are healthy eaters. I tell my husband that something is abnormal because his gas expulsion is the last thing I hear before going to sleep and the first sound in the morning. Would you please address the problem – if you are not laughing too hard? -W.F.

ANSWER: I am laughing a little, and that is simply because my sense of the laughable is fixated at about age 12.

An average person passes 500 to 1,500 milliliters (17-50 ounces) of gas a day in 10-20 episodes of gas expulsion. Gas comes from a number of sources. Bacteria in the intestine metabolize undigested food, especially carbohydrates, and produce gas as an end product. Some gas comes from swallowing air. If a belch does not get rid of it, then it makes its way through the digestive tract. A long list of foods generate gas, and the more notorious offenders are: onions, brussels sprouts, cauliflower, cabbage, asparagus, broccoli, prunes, apples, bananas, raisins, beans and fatty foods. In truth, just about every food except rice is a potential contributor to gas volume. Hydrogen, methane, carbon dioxide, nitrogen and oxygen are the major components of intestinal gas. All of them are odorless. A small amount of sulfur-containing gas accounts for the pungent odor.

There are some bona fide problems that lead to increased gas production. The inability to digest milk sugar, a problem with normal food absorption and constipation are examples.

For the healthy overproducer, simethicone preparations, available over-the-counter, are alleged to break up gas bubbles. Activated charcoal, obtainable in all drugstores, is said to sop up gas. Beano, a product that contains enzymes that break down carbohydrates, can diminish gas production. Although fiber is a key ingredient in a healthy diet, lowering the daily intake can help combat a gas problem. Not gulping food and moderating the amount of carbonated beverages lessens intestinal gas. Pepto-Bismol binds sulfur and essentially deodorizes gas. It should not be used regularly – only on occasions where gas-passing would be a social gaffe.

DEAR DR. DONOHUE: My husband has smoked a pipe for years. I have asked him not to smoke in the car or house because of the danger of secondhand smoke. He says that, unlike cigarette smoke, his smoke is not toxic because the pipe burns only natural tobacco.

Can this be right? – C.P.

ANSWER: I beg your pardon.

Does your husband mean that cigarette tobacco is unnatural tobacco?

I never knew and am presently doubtful that there is a difference between tobacco for pipes and tobacco for cigarettes.

Unless your husband can furnish evidence to prove his theory, I can’t buy it.

DEAR DR. DONOHUE: My wife and I have decided not to have any more children, since we already have seven. Our budget is strained as it is.

She wants me to have a vasectomy, and I want her to take birth control pills. I am reluctant to have the vasectomy because I have heard it leads to heart attacks. If you say otherwise, I’ll reconsider my stand. – J.J.

ANSWER: In the 1970s, reports circulated that suggested vasectomies might have a bearing on coronary artery disease – the plugging up of heart arteries – and subsequent heart attacks. Further investigations failed to show any relationship between the two.

DEAR DR. DONOHUE: What are these hideous brown spots on the backs of my hands? – P.B.

ANSWER: They are solar lentigines, products of sun exposure accumulated through the years. Doctors can freeze them off with liquid nitrogen, or they can be lightened with the use of Retin-A, an acne gel.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.