Expelling gas is important, especially for people unable to do so. When the lower esophageal sphincter (LES) is reinforced by anti-reflux surgery, belching may be impossible.
Swallowed air is lighter than food and most reaches only the esophagus. However, bedridden patients such as those recovering from surgery may trap air in their stomachs, becoming very uncomfortable. In the supine position (lying face upward) gastric contents seal the gastroesophageal junction so that air cannot escape.
Relief is achieved by lying face downward, in the prone position. Sometimes sleeping on the right side favors a therapeutic belch.
Repetitive belching is neither normal nor useful. While a person may insist that his or her stomach is producing large amounts of gas, in reality, air is repeatedly drawn into the esophagus and belched in the manner described above. A little may even reach the stomach.
Most sufferers are relieved to have their air-swallowing habit pointed out. Quitting is often difficult. Repeated and intractable belching has been termed eructio nervosa.