Diagnosis of achalasia
The incidence of achalasia is increasing over the recent decade due to the improvement of both the diagnosis methods and management strategies. Clinical investigation focused on symptom and severity evaluation is the fundamental step in the diagnosis algorithm. Upper endoscopy is a necessary examination for achalasia to rule out the malignancy and to determine a differential diagnosis. Barium esophagram shows the typical “bird beak” sign, and the time barium esophagram could provide a quantitative evaluation of esophageal luminal dilation and bolus retention. High resolution manometry (HRM) is the “gold standard” for achalasia, the updated Chicago classification defines the different subtypes of achalasia which are related to the treatment outcomes. The endoscopic functional luminal imaging probe (EndoFLIP) is a new technique which is able to measure the esophagogastric junction (EGJ) distensibility in achalasia patients and also a promising way to detect the contractility of the esophageal body among these patients.