What Can Be Done for Flatus on the Vegetarian Diet

By Milton G. Crane, M.D. and Barbara G. Crane, R.D. of Weimar Institute

Some people have difficulty with excess intestinal gas when they make a major change in their diet. Why is this? What can be done to relieve the situation other than to spend more time outdoors?

There are many different types of bacteria in the small and large bowels. Their job is to assist nature in recycling the food residue. On the usual American high-fat, high-sugar, low-fiber diet, certain types of yeast and bacteria predominate in the intestines. When a change is made to a low fat, no free sugar, high-fiber diet, another type of bacteria takes over. It may require several weeks, even up to a year, for the bacterial population to change over. For a while, the old type of bacteria will feed on the non-digestible carbohydrates like cellulose, stachyose, and raffinose and produce more methane, carbon dioxide, hydrogen, and certain other odiferous gases.

When the gas is formed, it may be absorbed into the blood and go out in the breath, or it may be expelled by the rectum. Since the residue of a high-fiber diet moves through the bowel two to three times as fast as that of a low residue diet, less gas will be absorbed and appear in the breath and more will go out the rectum. Fortunately, the nerve endings in the rectum are able to detect the difference between gas and the more liquid fecal material so that we can pass the gas without passing the liquid.

What can be done to relieve the situation? The following are some things that you can do to alleviate the problem.

Chew the fiber foods thoroughly. Most people who have lived on a soft, low residue diet for years do not realize the necessity for thorough mastication. Chewing grinds up the fibrous material, mixes the nutrients with salivary enzymes, and starts the digestive process. Until you have a well-ingrained habit and know what a thoroughly masticated mouthful should be like before swallowing it, you would be wise to count 30-50 chomps with each mouthful before swallowing it. This should be done even with soft foods like bananas. If you have poor teeth, blend what you must and "gum" it.

Treat legumes with special care. Start using legumes on the high-fiber diet with only small servings, at only one meal a day. Masticate them well even though they may be pureed. Chew them until not a particle of the bean or pea can be felt on the tongue. A good rule to follow is to chew each mouthful 30-40 times before swallowing. Some legumes, like lentils or cowpeas, are less likely to cause gas. It may be necessary to get rid of more of the pentose carbohydrates by special cooking process. Try soaking the legumes and discarding the soak water or let the beans sprout until the shoot is equal to the length of the bean before cooking. If that does not solve the bean problem, ask for additional suggestions.

Avoid overeating at any one meal. Do not overload the enzyme capacity of the digestive tract with too many calories. If you are overweight, excess gas may be a signal that you are eating too much.

Limit volume of food and frequency of eating. Two meals a day of modest volume or two main meals with one or two pieces of fruit for supper may solve the problem.

Avoid eating fruit and vegetables at the same meal. These are not digested at the same rate and may set up bloating. Cereal may be well tolerated with either fruit or vegetables, but eliminate any added bran.

Choose cooked vegetables rather than raw vegetables if you are unable to chew them thoroughly enough.

Go easy on certain foods or food combinations that are known to be gas formers. Salads, green peppers, radishes, cucumbers, broccoli, cabbage, cauliflower, brussel sprouts, or bananas. Beans and raw onions do not go well together. Some people cannot handle lactose in milk or milk products. If you must use these, try buttermilk or yogurt in which the lactose has been converted to lactic acid.

Avoid a large variety of foods at any one meal. More than three or four different foods or complex recipes may be difficult to digest.

Avoid cold drinks, carbonated beverages, and icy desserts. These may temporarily slow down digestion and allow time for fermentation in the intestines.

Try to avoid eating when angry or under stress. A merry heart doeth more good than antacids.

Study your own body. Each person has certain idiosyncrasies. For example, if I eat a legume for breakfast and lunch, I cannot eat apricots or apples (with peeling) for supper without terrible trouble.

Two to four, six-gram tablets of activated charcoal can considerably decrease the amount of gas. Charcoal is not absorbed and has no systemic effects. Watch out, though, chronic use may interfere with absorption of certain essential elements and vitamins.

Certain ailments may cause digestive fullness after a meal. Consult your physician if there is any question.

Copyright © 1995-2002 Milton G. Crane, M.D. and Barbara G. Crane, R.D., Weimar Institute, Weimar, CA 95736. All rights Reserved.