On the day of esophageal motility testing an EFT probe will be placed transnasally through the esophagus into the stomach and the LES location and pressure will be determined by stationary pull-through technique. The most distal circumferential pressure sensor will be placed in the high-pressure zone (HPZ) of the LES. The other measuring sites (both pressure and impedance) will be subsequently at 5, 10, 15 and 20 cm above the HPZ of the LES. Ten swallows (5 cc each) of liquid (0.9% normal saline) and 10 swallows (5 cc each) of a standard viscous material (EFT viscous, Sandhill Scientific, Inc) will be given with each swallow 20-30 seconds apart.