Achalasia Overview Achalasia Achalasia is caused by failure of the lower esophageal sphincter to relax. Inhibition of the lower esophageal sphincter is mediated by NO and VIP released from inhibitory neurons within the sphincter muscle. Degeneration of these neurons results in tonic sphincter contraction. Symptoms are caused by food becoming trapped in the esophagus and unable to pass into the stomach. With time, the esophagus can become enlarged with marked tortuosity to accommodate the retained food.
Patients can present with dysphagia, regurgitation of undigested food, and even chronic aspiration.