The goal of this prospective study is to validate a high resolution manometry score to predict pathologic GERD in patients with reflux symptoms. The main question it aims to answer is:

Is it possible to predict GERD on high resolution manometry? Participants will be asked to undergo high resolution manometry and pH-study

According to recent guidelines, high resolution manometry (HRM) has an ancillary role in the diagnosis of gastro-esophageal reflux disease (GERD). A recent multicenter study demonstrated the effectiveness of the straight leg raise (SLR) maneuver in predicting GERD, thus increasing the diagnostic value of HRM in patients with suspected pathological reflux. HRM parameters associated with GERD include esophageal body hypomotility such as ineffective esophageal motility (IEM), and esophagogastric junction (EGJ) metrics, particularly the EGJ contractile integral (EGJ-CI) that takes into consideration the presence or absence of a hiatal hernia (HH), and a hypotensive lower esophageal sphincter (LES). The combination of these four parameters might help to predict or exclude true GERD in patients undergoing HRM with the suspicion of GERD.

In this multicenter international prospective study, we aimed to build a score to predict pathological esophageal acid exposure time (AET>6%).

Inclusion Criteria:

• HRM and wireless pH-study or catheter pH-impedance study performed for persistent GERD symptoms off proton-pump inhibitor (PPI) within two weeks of each other,
• SLR maneuver performed at the end of HRM

Exclusion Criteria:

• Body mass index (BMI) >35 Kg/m2
• prior esophageal surgery
• paraesophageal hiatal hernia
• eosinophilic esophagitis
• scleroderma
• esophageal achalasia