FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

CHANGE IN DIET AND AGING CAN PRODUCE INCREASED FLATULENCE

Question: I have a problem with intestinal gas. I always feel bloated and frequently burp and pass gas, regardless of what I eat. I haven't always been this way, so what could be causing this?

Answer: As I'm sure you've noticed, everyone occasionally passes gas. On average, most healthy men and women have about 10 episodes of flatulence per day and, occasionally, as many as 20.

Gas in the stomach is usually a result of swallowing air along with food or drink, or from the dissolved gas we take in by drinking carbonated beverages. The "fizz" we all love in our carbonated beverages is actually carbon dioxide gas that's been dissolved in the water. Once in the stomach, it comes out of the liquid and collects as bubbles of gas. Too much gas in the stomach, from whatever the cause, typically causes bloating and belching.

Gas in the small intestine, on the other hand, is usually a product of digestion of the food we eat. Gas in the colon the large intestine is usually a consequence of bacterial action upon food residue that was not absorbed in the small intestine. It is gas that originates in the small intestine or the colon that causes the socially unacceptable, yet totally unavoidable, episodes of flatulence.

Gas in the colon may be partially absorbed and carried from the body with each exhaled breath. Other gas, particularly hydrogen, is used by other colon bacteria to form methane. The remaining gas largely hydrogen, carbon dioxide and methane escapes from the rectum as flatulence. It is a wonder that we humans don't suffer a Hindenburg-like disaster every day from the amount of hydrogen we expel!

Colon gas is increased when the small intestine is unable to absorb carbohydrates, which are then passed into the colon and used by bacteria as food. A very common cause of this is the carbohydrate lactose - also called "milk sugar" - that is present in dairy products. It is poorly digested by at least three-fourths of all adults. This may be the reason you now have more flatulence than you did when you were younger.

Some of the carbohydrates in wheat, oats, corn, potatoes and beans may also be poorly absorbed. The resident bacteria of the colon have a feast when these indigestible components pass into the colon, and you know what this causes. Yes, more flatulence. Rice seems to be the only grain that has carbohydrates that are totally digestible by healthy individuals and, therefore, doesn't cause flatulence.

Fortunately, it is not necessary to avoid these common nutritious foods. Those who have problems with milk or products made from milk can take the enzyme lactase, sold under the brand name Lactaid, before they consume the offending dairy products. This enzyme enables the small intestine to absorb the milk sugar for our nutrition instead of letting it move to the colon. Another product provides the enzyme alpha-galactosidase, sold as Beano, to help digest the carbohydrates of beans and other grains.

Your complaints are probably a consequence of your subtly changing metabolism and your diet. I am concerned, however, about the possibility of other health problems. Individuals with a poorly functioning gall bladder, or those with colon cancer, report a two-fold increase in the symptoms of bloating and gas. It would be wise to check with your family doctor to make sure your discomfort is not due to one of these causes.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.