Achalasia

**Definition:** Achalasia is an oesophageal smooth muscle motility disorder characterised by a loss of peristalsis in the distal oesophagus and a failure of lower oesophageal sphincter (LES) relaxation. Basic mechanism is the degeneration of neurons (ganglion cells) in the myenteric plexuses in the oesophageal wall, but the cause is still unclear.

**Inclusions:** - Cardiospasm

**Exclusions:** - congenital cardiospasm