Coordinating Center: Natural History of Barrett's Esophagus Using Tethered Capsule Endomicroscopy

Inclusion Criteria: * Participants over the age of 18 * Participants who are capable of giving informed consent * Participants with a diagnosis of BE without high grade dysplasia, intramucosal adenocarcinoma or esophageal adenocarcinoma, confirmed by endoscopic biopsy * Participants who had or will have a standard of care EGD within 15 months, exceptions to this can be submitted to the coordinating center (MGH) for approval Exclusion Criteria: * Participants with prior endoscopic ablation or resection treatment of BE at enrollment visit * Participants with esophageal fistula and/or esophageal strictures * Participants with the inability to swallow capsules * Concomitant chemotherapy treatment * Self reported pregnancy