Pam Descher, age 11, of Enid, Okla., for her question:

WHAT MAKES A PERSON BURP?

A common burp or blech usually comes from the swallowing of air or from gas in the stomach that is caused by the chemical reactions of food and digestive juices.

An abnormal accumulation of gas, or flatus, in the stomach or intestine is called flatulence. The adult stomach normally contains a bubble of gas amounting to about half a pint. Any excess is generally discharged by belching, or eructation.

The presence of the gas is commonly ascribed to swallowing of air and it is true that some people, by relaxing certain muscles of the esophagus and abdominal wall, can voluntarily fill the stomach with surprisingly large volumes of air.

Certain foods are well known as tending to cause flautulence. Included are beans, cabbage and cucumbers.