Achalasia Achalasia of the oesophagus A disorder of esophageal motility characterized by the inability of the lower esophageal sphincter to relax during swallowing and by inadequate or lacking peristalsis in the lower half of the body of the esophagus. HP:0002571 SNOMEDCT_US:45564002 UMLS:C0014848 Achalasia may lead to regurgitation of food, chest pain, cough, and difficulty swallowing. Achalasia of the esophagus MEDDRA:10030136 Ineffective esophageal peristalsis