rimary spastic esophageal motility disorders, though uncommon, induce significant symptoms to patients including dysphagia, spastic chest pain, regurgitation as well as heartburn. The commonest causes of spastic esophageal motility disorders included Achalasia, hypertensive lower esophageal sphincter (LES), Nutcracker esophagus and Diffuse esophageal spasm (DES). Majority of these diseases were diagnosed by manometry. Achalasia is the most common primary esophageal motility disorder in which the LES failed to relax with increased pressure. Currently the standard treatment for Achalasia and spastic motility disorders is Laparoscopic Myotomy. The development of Natural Orifices Transluminal Endoscopic Surgery (N.O.T.E.S.) has lead to a new way to perform myotomy - Peroral Endoscopic Myotomy (P.O.E.M.). Basically, through mucosal incision, a submucosal tunnel is created after identification of the level of gastroesophageal junction. Myotomy will be performed with endoscopic instruments and the entrance site will be closed with clips.

Inclusion Criteria:

• All patients with age ranged 18 to 85 who had primary esophageal motility disorders will be recruited. The primary motility disorders included: Achalasia, hypertensive LES, Nutcracker esophagus and Diffuse esophageal spasm.

Exclusion Criteria:

1. Pregnancy
2. Informed consent not available
3. Previous history of esophagectomy or mediastinal surgery
4. Previous history of endoscopic resection for early esophageal cancers, inclduing endoscopic mucosal resection and endsocopic submucosal dissection
5. End-stage Achalasia with dilated esophagus more than 6cm on Barium swllow