Figure.

As a rule, endoscopy is the first step in diagnosing the cause of dysphagia. It can also be used to rule out secondary achalasia, e.g. inflammation, stenosis, or tumors, and to obtain tissue biopsies. However, if there are grounds in the patient’s medical history for suspecting a stricture, e.g. caused by radiation or chemical burns, a barium swallow and X-ray of the esophagus are recommended first, as endoscopy poses a higher risk of perforation. In such cases, endoscopy is performed only to rule out secondary achalasia. Once secondary achalasia has been ruled out endoscopically, an esophageal manometry and/or barium swallow and X-ray of the esophagus are performed