 A total of 130 subjects scheduled to undergo esophagogastroduodenoscopy EGD will be asked to swallow the OFDI capsule while being unsedated. The capsule is attached to a tether that allows the capsule operator to navigate the capsule as it progresses down the esophagus using natural propulsion called peristalsis as well as to bring it back up to pulled out of the mouth when the procedure is done. 