The per-oral endoscopic myotomy, or POEM, is a minimally invasive surgical procedure for the treatment of achalasia wherein the inner circular muscle layer of the lower esophageal sphincter is divided through a submucosal tunnel. This enables food and liquids to pass into the stomach, a process that is impaired in achalasia. The tunnel is created, and the myotomy performed, using a flexible endoscope, meaning the entire procedure can be done without external incisions. (Wikipedia).
