Gastroesophageal reflux disease (GERD) is a common condition affecting more than 100 million adults in the U.S., and it significantly impacts patients' quality of life while imposing billions of dollars of direct and indirect costs each year upon our healthcare system. Current diagnostic tests for GERD are highly invasive and medically inadequate, and the goal of this project is to develop a novel, minimally invasive Mucosal Impedance technique for more accurate detection of GERD while reducing costs.