Certain foods are more likely to cause certain colonic bacteria to thrive. Some of these bacteria are called "gas formers." They generate gases such as hydrogen and methane. As much as 90%t of rectal gas is formed by these bacteria. Gas forming bacteria generally feed on certain carbohydrates and sugars. So, if these carbohydrates are reduced or eliminated from the diet, rectal gas can usually be significantly reduced. Individual response to certain foods is also a factor in producing rectal gas. For instance, two people can eat the same amount of the same carbohydrate. One forms large amounts of rectal gas, while the other experiences little or none.

Go low on high-fructose corn syrup: Foods containing this sweetener can cause bloating and flatulence in people whose small intestines can't absorb large amounts of fructose.

The Intestinal Gas Trial Diet:

A trial diet may be conducted in one of two ways:
1. Continue to eat as you normally do, but eliminate one category of gas producing foods for at least a week. If there is no lessening of gas, put the foods back in the diet and go on to eliminate another category for a week. Follow this procedure until reaching a level of gas that is tolerable.
2. Restrict all categories of foods that cause gas for 3 or 4 days. Then reintroduce one food at a time back to the diet, and continue to include this food for 3 or 4 days. If the selection causes no problems, it may be kept in the diet. If there is marked increase in gas production, eliminate it and go on to the next food. Continue this process until all foods causing gas are identified, and then avoid them..

The worst offenders are:

• Legumes (most beans, especially dried beans and peas, baked beans, soy products/beans, lima beans)
• Milk & milk products (milk; ice cream; and cheese)
• Vegetables (cabbage; radishes; onions; broccoli; Brussels sprouts; cauliflower; cucumbers; sauerkraut; kohlrabi; asparagus)
• Root vegetables (potatoes; rutabaga; turnips)
• Fruits (prunes; apricots; apples; raisins; bananas)
• Cereals, breads (all foods thst contain wheat and wheat products including cereals, breads, and pastries)
• Fatty foods (pan-fried or deep-fried foods; fatty meats; rich cream sauces and gravies; pastries)
• Liquids (carbonated beverages, medications, or powders).

Slow down your eating: A little bit of air goes down with everything you swallow. To reduce the amount of air, eat and drink slowly and chew food thoroughly.

Avoid airy drinks and foods: Air also gets into the gut if it's incorporated into food and drinks like beer, soda, or sponge cake.