Endoscopic Esophageal Myotomy (POEM), the research procedure, splits the lower esophageal sphincter muscle fibers from the inside of the esophagus, avoiding several abdominal incisions (belly area cuts), by using an endoscope to create a small cut at the most inner layer of the esophagus to expose the esophageal sphincter muscle fibers from the inside of the esophagus. The investigators are studying whether subjects who undergo Endoscopic Esophageal Myotomy will have similar functional outcome, and at the same time less pain, scar formation and wound infection than with laparoscopic or open surgery.