How much gas do we pass?

The answer is c. Our bodies normally produce between 7 and 10 liters of gas, which contains oxygen, carbon dioxide, hydrogen, and methane.

Most of this gas is reabsorbed into the blood stream, leaving only about 600 milliliters to escape, roughly 2½ cups. Most of this escapes our bodies without us even realizing it, but sometimes it leaves in an unmistakable, ahem, fashion -- usually in the form of burping or flatulence. When this happens more than usual, people complain they have excessive gas, thinking their bodies are producing more, which is generally not the case.

Bloating, cramping and the feeling of extra gaseous emanations are usually the result of decreased intestinal motility, meaning the bowels aren't moving their contents along fast enough. A sudden increase of fiber in the diet can cause the intestines to slow down and gas to build up, but eventually the body adjusts.

Dietary fiber is the indigestible portion of foods such as leafy greens, fruits and vegetables that slow the food down on its way through the digestive tract, giving the intestines their necessary workout to stay in shape.

Some soluble fibers, such as oats, also help inhibit the absorption of cholesterol. The National Cancer Institute recommends a healthy average dietary fiber intake of 25- 35 grams a day, which can usually be met by eating 5 servings of fruits or vegetables a day. Beans, bananas, spinach, apples and raspberries contain between 2 and 4 g each per serving, and pasta, cereals and bran muffins pack it in, as well.

Read more on the topic:

Flatulence explained in a Salon magazine profile of Dr. Michael D. Levitt (aka Dr. Fart), of the Minneapolis Veterans Affairs Medical Center.

Get a technical description of the fiber/flatulence connection in this article from the Health Care Reality Check Web site.

April 20, 2002