Post-per-oral endoscopic myotomy heartburn: It's not always reflux: Expert review.

Patients with achalasia frequently develop gastroesophageal reflux (GER)-related symptoms and complications after per-oral endoscopic myotomy (POEM). Reflux symptoms are thought to be due to GER and the current treatment of post-POEM GER focuses on acid suppression with proton pump inhibitors (PPI). However, reflux symptoms in achalasia patients post-POEM can be due to true reflux, nonreflux esophageal acidification due to stasis or acid fermentation, or esophageal hypersensitivity to chemical or mechanical stimuli. True acidic reflux is not always the cause of reflux symptoms. Twenty-four-hour pH monitoring with impedance is essential to differentiate causes of esophageal acidification. PPI is useful only in true acidic reflux. Detection of acid fermentation requires manual review of a 24-h pH study, as automated review often overestimates acid exposure time due to its inability to differentiate true reflux from fermentation. Stasis of ingested acidic food warrants evaluation of esophageal emptying by timed barium esophagogram. In cases of inadequate emptying, esophagogastric junction (EGJ) distensibility can be evaluated by a functional lumen imaging probe. Impaired distensibility with inadequate esophageal emptying suggests treatment failure and may require retreatment. In treatment-refractory patients, esophageal hypersensitivity should be considered and treated with neuromodulators. Thus, the diagnostic approach to post-POEM reflux symptoms should evolve to identify various patterns of esophageal acidification, esophageal emptying patterns, EGJ distensibility, and hypersensitivity. Consequently, the treatment of GER post-POEM should not be limited to treating esophageal acidification by reflux, but should encompass other causes of acidification and esophageal hypersensitivity.