Since Inoue performed the first POEM in 2008, safety and efficacy have been well-established. Early studies focused on refining the technique and avoiding incomplete myotomy. Following the discovery that many patients with abnormal acid exposure are asymptomatic, the focus shifted to post-POEM reflux, but no studies have identified any associated procedural factors. In this study, we examined the intermediate-term results of our previous randomized controlled trial, with particular attention to post-POEM reflux.