The investigators have developed a tethered capsule OCT device intended as an inexpensive screening tool for BE. The capsule, which is attached to a thin, flexible tether, is reusable after being processed by a standard disinfection technique. Used without sedation, the capsule is swallowed by the participant and travels in the esophagus to the gastroesophageal junction (GEJ) via peristalsis. Cross-sectional microscopic OCT images of the entire esophagus are collected during transit. The total time needed for swallowing, imaging and retrieval does not exceed 10 minutes, with a total of 30 minutes for the procedure. The investigators have tested the feasibility and the tolerability of this new OCT screening technology in 250 procedures in healthy volunteers and participants with various esophageal diseases including BE. The procedure has been safe and well tolerated. High quality microscopic images of the esophagus have been obtained in 90% of the enrolled participants.