Conventional Esophageal manometry is a well defined and standardized exam in the clinic of the pathophysiology of the esophagus, through the study of the upper esophageal sphincter (UES ), the study of the lower esophageal sphincter (LES) and the study of the esophageal body . This examination involves the use of catheters with to 4 or 8 channels and different position of the measuring points along the catheter.