Patients with aerophagia are believed to have excessive belches due to air swallowing.
Researchers from the Netherlands undertook a study into aerophagia using intraluminal impedance monitoring.
The research team measured esophageal pH and electrical impedance before and after a meal in 14 patients with excessive belching and also in 14 healthy controls.
The researchers were then able to identify patterns of air transport through the esophagus.
The size of the gastric air bubble was measured radiographically.
The researchers performed prolonged esophageal manometry simultaneously in 4 patients.
The researchers were able to show from the impedance tracings that, in all subjects, a significant amount of air is propulsed in front of about a third of the swallow induced peristaltic waves.
Excess belching activity follows a distinct pattern: rapid antegrade and retrograde air flow in the oesophagus that does not reach the stomach
The team observed two types of retrograde gas flow through the esophagus (belch).
In the first type air flowed from the stomach through the esophagus in oral direction ("gastric belch").
In the second type air entered the oesophagus rapidly from proximal and was expulsed almost immediately in oral direction ("supragastric belch").
The researchers found that the incidence of air-containing swallows and gastric belches was similar in patients and controls.
However, supragastric belches occurred exclusively in patients reported as having excessive belching.
There was no evidence of lower esophageal sphincter relaxation during supragastric belches.
Gastric air bubble size was not different between the two groups.
Dr Bredenoord concluded, "In patients with excessive belching the incidence of gaseous reflux from stomach to esophagus is similar to that in healthy subjects."
"Their excess belching activity follows a distinct pattern, characterized by rapid antegrade and retrograde flow of air in the esophagus that does not reach the stomach."