Belching and Reflux: The Relationship and the Underlying Mechanism

: Belching can occur either independently or concurrently with reflux symptoms. This study aims to explore the relationship between belching and reflux and explore the underlying mechanisms involved.

: Firstly, patients with isolated belching symptoms or concurrent belching and reflux symptoms were retrospectively enrolled. High-resolution esophageal impedance manometry (HRIM) and 24-hour pH impedance monitoring were used to assess belching types and temporal relationship between belching and reflux. Secondly, subjects with belching disorder were prospectively recruited. Postprandial HRIM monitoring was used to clarify the relationship and underlying mechanisms between belching and reflux.

: In the initial phase, 139 subjects were enrolled. Regardless of patients' symptom spectrum (with or without gastroesophageal reflux symptoms), the proportion of preceding-reflux belching was significantly higher in those with objective evidence of gastroesophageal reflux disease, compared to those without (both P < 0.05), which indicated that belching could trigger reflux events and led to more severe reflux burden. To clarify the potential mechanisms involved, 44 belching subjects were prospectively enrolled in the second phase of this study. HRIM analysis demonstrated that maximum intragastric pressure, gastric-lower esophageal sphincter pressure gradient and gastric-esophageal pressure gradient were significantly higher in preceding-reflux belching than those in independent belching.

: This study demonstrated that belching might trigger reflux by increasing intragastric pressure, elevating the gastric-sphincter pressure gradient, which enables gastric contents to pass through the esophagogastric junction. These findings have crucial clinical significance, suggesting that reducing the occurrence of belching might be a potential treatment for refractory reflux.