achalasia

Achalasia, also known as esophageal achalasia, achalasia cardiae, cardiospasm, dyssynergia esophagus, and esophageal aperistalsis, is an esophageal motility disorder.[1] In this disorder, the smooth muscle layer of the esophagus has impaired peristalsis (muscular ability to move food down the esophagus), and the lower esophageal sphincter (LES) fails to relax properly in response to swallowing.[2] The most common form is primary achalasia, which has no known underlying cause. However, a small proportion occurs as a secondary result of other conditions, such as esophageal cancer or (in South America) Chagas disease.