Gas in the digestive system comes from swallowed air or the breakdown of undigested food in the colon. According to the National Digestive Diseases Information Clearinghouse, most people produce one to four pints of gas per day and pass gas about 14 times. When you belch, your body is releasing excess gas from the upper end of your digestive system: the esophagus and stomach.
Belching
Belching, or burping, usually results when you swallow extra air along with your food. This is called aerophagia. The burp is just a gas bubble made up of nitrogen, oxygen and carbon dioxide. MedlinePlus explains that the pressure of the air at the top of the stomach makes the lower esophageal sphincter---the valve that keeps the flow of traffic going in one direction---relax, which allows the air to escape.
Causes
Beer and carbonated soda produce gas bubbles that will make you burp. If you eat very fast and don't chew your food much, you will probably swallow more air than a slower eater. Chewing gum, eating hard candy and smoking will also increase the amount of air you swallow. Acid reflux or gastroesophageal reflux disease can cause belching because you might swallow frequently to clear a buildup of stomach acid in the esophagus, which increases the amount of air in your belly and makes you burp. You could also have a nervous habit of swallowing when you aren't eating.
Prevention
To minimize your burping, try eating slower and chewing food more thoroughly. Don't talk while eating---wait until you swallow your food to start talking. Stay away from gum, hard candies and cigarettes. Avoid fizzy sodas, beer and champagne. Try eating less food at each meal or eating five mini-meals a day instead of two or three large ones to avoid overfilling your stomach. If you suffer from heartburn, take antacids to cool your symptoms instead of repeatedly swallowing to clear stomach acid.
Cautions
Belching is usually not a serious issue, but there are a few cases when you should contact your doctor. If you feel like you are belching all the time and you don't understand why, or if you also have other digestive symptoms like bloating, abdominal pain, nausea, vomiting, diarrhea, weight loss, fever or chest pain, then you may have an underlying health issue.
