Peroral endoscopic myotomy (POEM) has become the mainstay of treatment of esophageal achalasia in recent years. As the direct consequence of myotomy is the decrease of the pressure of the lower esophageal sphincter (LES), gastroesophageal reflux has become a concern. Standard POEM is not accompanied by an antireflux procedure, unlike laparoscopic Heller myotomy (LHM) which is usually combined with Dor fundoplication. Uncertainties regarding the long-term implications of reflux somehow hampered the enthusiasm about treating achalasia with POEM.

Although the evaluation and management of post-POEM reflux seems straightforward, there are some issues related to this phenomenon. Firstly, the evaluation of reflux after POEM is a challenge as there are different approaches, namely by the presence of heartburn (reported by the patients themselves), erosive esophagitis (endoscopy), and acid exposure time (AET) by pH monitoring. These aspects of gastroesophageal reflux correlate poorly. Secondly, since the first report on the POEM procedure back in 2010 [1], there has been a concern about the long-term consequences of gastroesophageal reflux, namely the incidence of peptic stricture and Barrett's esophagus/esophageal adenocarcinoma. Thirdly, about the treatment of post-POEM reflux, indications for proton pump inhibitor (PPI) therapy are not well defined, nor are the recommendations for reflux refractory to PPI.

We will use the term post-POEM reflux in this review to highlight the difference from gastroesophageal reflux disease (GERD) as GERD has a complex pathophysiology in which the lower esophageal sphincter is an important, yet not the only determining antireflux element.