Esophageal mucosal acid sensitivity can coexist with normal pH recording in healthy adult volunteers

We aimed to determine whether healthy volunteers with normal pH monitoring study results experienced heartburn or discomfort during an esophageal acid perfusion test. We performed an esophageal acid perfusion test, followed by ambulatory esophageal pH monitoring, in 15 healthy and asymptomatic volunteers (aged 19 to 34 years). The results of the acid perfusion test were correlated with those of the pH monitoring. Three subjects (20%) reported chest discomfort during acid perfusion. The pH data in all subjects were within our laboratory reference ranges; the median (range) percent total time at pH < 4 being 1.7 (0.2-4.0)% [laboratory reference, median (range), 3.0 (0.2-4.0)%]. We concluded that direct infusion of acid onto the distal esophagus can produce discomfort akin to that of gastroesophageal reflux disease in asymptomatic adult volunteers, even in the absence of excessive esophageal acid exposure.