Belching removes gas from your stomach by forcing it into your esophagus and then out your mouth. Swallowing too much air can cause bloating or frequent belching. If you belch repeatedly when not eating, you may be swallowing air as a nervous habit. Usually the gas is expelled during a bowel movement. The foul odor usually is the result of small traces of other gases such as hydrogen sulfide and ammonia and other substances.
Swallowed air makes up a small fraction of intestinal gas.
Carbonated drinks may release carbon dioxide in the stomach and may be a source of gas. Gas Pains Sharp, jabbing or crampy pains in your abdomen may be caused by the buildup of gas. They often occur in the right lower and left upper abdomen and change locations quickly. Passing gas sometimes relieves these pains. Any of the sources of intestinal gas or diarrhea can lead to gas pains.