Effect of Carbonated Water on Esophageal Motility in Different Body Positions: A Study Based on High-Resolution Manometry.

Background: Carbonated water has long been a popular beverage, but its impact on esophageal motility remains unclear. This study aimed to evaluate the effect of carbonated water using high-resolution esophageal manometry (HRM).

Methods: A standard HRM protocol, incorporating measurements in both supine and upright positions per the updated Chicago Classification v4.0, along with additional carbonated water swallows, was performed in our motility laboratory. Ineffective esophageal motility (IEM) was diagnosed based on > 70% ineffective swallows or ≥ 50% failed peristalsis in the supine position and categorized as "Supine IEM (SI)". Patients who met the IEM diagnostic criteria in the upright position but not in the supine position were classified as "Upright Ineffective (UI)" for further comparison.

Key results: A total of 62 patients were found to have ineffective motility, with 30 diagnosed with IEM (SI group) and 32 categorized as UI. Compared with the standard water swallows, carbonated water increased the median DCI in the upright position (130 vs. 208 mmHg·cm·s, p < 0.001). It also reduced the proportion of failed peristalsis (85% vs. 65%, p < 0.01) and ineffective swallows (94% vs. 69%, p < 0.001) during upright swallows. The number of ineffective motility cases was reduced from 30 to 26 in the SI group, indicating a 13% improvement, and from 32 to 22 in the UI group, representing a 31% improvement (p < 0.01).

Conclusions and inferences: Carbonated water significantly improves esophageal motility, particularly in the upright position. This effect is more pronounced in patients with upright ineffective motility.