Other people swallow air without noticing it, especially when they are tense. In this case air is not swallowed into the stomach but sucked into the gullet and rapidly expelled. Repetitive belching like this can last for minutes at a time and is very embarrassing. It is nearly always due to stress or anxiety. Air cannot be sucked in when the jaws are separated, so repetitive belching can be temporarily controlled by firmly clenching something like a pencil between the teeth.
Some people develop aerophagy because of discomfort in the chest.
B loating Abdominal bloating is a common complaint often blamed on excess gas in the bowel. Research has shown that when small amounts of gas are infused into the intestine, people with irritable bowel syndrome develop bloating and pain, whereas other people tolerate the same or even larger amounts of gas without any discomfort. How distention of the gut is perceived as bloating is not known. Bloating may also be caused by rich fatty meals which delay stomach emptying. Bloating is often associated with abdominal distension so that skirts or belts have to be loosened.