Effect of MIST on Esophageal Sensitivity in Patients With rGERD

Inclusion Criteria: * Aged between 18 to 65 years; * Patients need to be classified as having gastroesophageal reflux disease and can be divided in three different groups (based on the Lyon consensus): * True GERD: Acid exposure time (AET) \>6% off PPI or \>80 reflux episodes on PPI * RHS: AET \<4% off PPI or \<40 reflux episodes on PPI and positive symptom association * FH: AET \<4% off PPI or \<40 reflux episodes on PPI and negative symptom association --\> Result based on a measurement maximum 1 year ago. * Subjects must be capable of understanding and be willing to provide signed and dated written voluntary informed consent before any protocol-specific screening procedures are performed. * Being able to stop PPI intake for 10 - 14 days before the study visit. Exclusion Criteria: * Endoscopic signs of severe erosive esophagitis (grade C or D, Los Angeles classification) on endoscopy performed off PPI treatment in the 12 months prior to screening, or ≥ grade B when endoscopy is performed on PPI treatment; * Systemic diseases, known to affect esophageal motility (i.e. systemic sclerosis); * Surgery in the thorax or in the upper part of the abdomen (appendectomy and cholecystectomy are allowed); * Significant neurological, respiratory, hepatic, renal, hematological, cardiovascular, metabolic or gastrointestinal cerebrovascular disease as judged by the investigator; * Severe anxiety/depressive disorder (assessed with the GAD7, PHQ9 and PHQ15); * Medication intake tha…