How to Distinguish Idiopathic Achalasia from Pseudoachalasia?

Achalasia is a disorder characterized by insufficient relaxation of the lower esophageal sphincter and absent peristalsis. It is usually primary (idiopathic) achalasia, but it can also be secondary achalasia (pseudoachalasia). With a review of the literature, epidemiological data was gathered on achalasia in this paper, and followed up with presented etiopathogenetic mechanisms of achalasia.