Belching is the way most swallowed air leaves the stomach. The remaining gas is partially absorbed into the small intestine and a small amount goes into the large intestine and is released through the rectum. The undigested or unabsorbed food then passes into the large intestine, where harmless and normal bacteria break down the food. This process produces hydrogen, carbon dioxide, and, in about one-third of all people, methane gases, which are released through the rectum. The following are the most common symptoms for gas, however, each individual may experience symptoms differently.
Chronic symptoms caused by too much gas or by a serious disease are rare.
It is characterized by severe air swallowing and an enlarged bubble of gas in the stomach following heavy meals. Fullness and shortness of breath caused by this disorder may mimic a heart attack. The surgery creates a one-way valve between the esophagus and stomach that allows food and gas to enter the stomach. Passing gas through the rectum is called flatulence. Passing gas 14 to 23 times a day is considered normal.