1. INTRODUCTION Gastro-esophageal reflux disease (GERD), defined as the presence of symptoms or lesions that can be attributed to the reflux of gastric contents into the esophagus, is an increasingly prevalent condition in Western societies. The most typical symptoms are heartburn and regurgitation, but GERD can manifest itself through a variety of esophageal and extra-esophageal symptoms (e.g. chronic cough).