[Study on correlation between postures and gastroesophageal reflux].

Simultaneous esophageal and gastric manometry and intraesophageal pH monitoring were performed in 12 patients with gastroesophageal reflux diseases in order to compare the frequency and mechanism of reflux in upright and supine postures. It was found that there was no differences in the number of reflux episodes, acid clearance time and percentage time of pH below 4 (P > 0.05). Frequency of reflux associated with lower esophageal sphinter relaxation (LESR) and gastric press increase was similar in two postures (P > 0.05). The results suggest that upright reflux may be as important as supine reflux in the development of reflux esophagitis. The main machanism of reflux in the two postures is LESR. Increase of gastric press may be a factor leading to gastroesophageal reflux.