Diagnosis of symptomatic gastroesophageal reflux by prolonged monitoring of lower esophageal pH.

Lower esophageal pH was continuously monitored for 15 hours in 10 asymptomatic subjects and 27 patients with symptoms of gastroesophageal reflux, and the pH measurements in symptomatic patients were compared with the results of other esophageal investigations. Symptomatic patients had significantly longer periods of reflux in the pH test than asymptomatic subjects (P less than 0.01), but there was no significant correlation between the pH measurements and the results of esophageal manometry, acid-perfusion, and acid-clearing tests. Ten patients had evidence of esophagitis at esophagoscopy, but there was no correlation between pH measurements and the findings at esophagoscopy. Two patients with esophagitis had no evidence of reflux in the pH monitoring test. The results indicate that the pH-monitoring test has a useful role in the diagnosis of gastroesophageal reflux in patients who do not have endoscopic signs of esophagitis. However, negative pH tests do not exclude the diagnosis of symptomatic reflux, and it appears that the test has no value in assessing the severity of esophageal inflammation.