Abstract
Intraluminal pH in the lower esophagus has been recorded during a 3-hr period following a light meal and a consecutive 12-hr nocturnal period in 20 patients with typical symptoms and radiological evidence of gastroesophageal reflux and in 10 patients without such signs of reflux. Evidence of acid reflux was obtained in 3 of the patients without reflux during the postcibal period but in only one during the 12-hr nocturnal period. In contrast all except one of the 20 patients who had evidence of reflux showed spells of high acidity both in the postcibal and nocturnal periods. There was no clear correlation between the frequency of pain from gastroesophageal reflux over the preceding two weeks and the duration of high acidity in the nonturnal period. Those patients with endoscopic evidence of severe esophagitis showed a significantly longer duration of high esophageal acidity in the nocturnal period. We conclude that nocturnal exposure of the esophageal mucosa to acid is a major factor in the causation of reflux esophagitis.