Digestive physiopathology is a branch of gastroenterology aiming to study patients with upper GI symptoms, mainly gastro-esophageal, potentially indicating the presence of Gastroesophageal Reflux Disease (GERD)/Barrett Esophagus (BE) or obstructive esophageal motility disorders (achalasia being the most relevant), but including also other primary motility disorders such as Esophgago-Gastric Junction Outflow Obstruction (EGJOO), Hypercontractile Esophagus (HE), Distal Esophageal Spasm (DES) and other minor disorders. Physiopathological testing encompasses High-Resolution Manometry (HRM), 24-H esophageal pH-impedance testing, Functional Lumen Imaging Probe (FLIP) assessment. All these tests are designed to provide a clear phenotyping of esophago-gastric disorders related to reflux or obstructive esophageal symptoms, either in naïve patients, as well as after foregut surgery (particularly anti-reflux surgery, achalasia/primary motility disorders treatment).