Cytosponge Adequacy Study Evaluation II

Inclusion Criteria: 1. Male or female subjects, age 18 and above. 2. Able to read, comprehend, and complete the consent form. 3. Clinically fit for an endoscopy. 4. a) Previous confirmed diagnosis of Barrett's esophagus with intestinal metaplasia, and Prague classification of at least one circumferential centimeter of BE or a total BE segment length of at least 3 centimeters (C1+ or CXM3+) (BE arm) . OR b) If the subject does not have documented Prague Classification prior to screening, but the PI is convinced that the subject will meet the inclusion criteria based on previous documentation (for instance, mention of "long-segment BE," they may enroll the subject in the study at their discretion. The study upper endoscopy must confirm that the subject has C1+ or CXM3+ (BE arm). If (C1+ or CXM3+) is not observed at the time of study endoscopy, the subject may still be enrolled but not included in the data analysis with the BE cohort. The data may be analyzed in a separate cohort. OR c) Self-reported heartburn or regurgitation on at least a monthly basis for at least 6 months (GERD arm). Exclusion Criteria: 1. Individuals with a diagnosis of an oropharynx, esophageal or gastro-esophageal tumor, or symptoms of dysphagia. 2. Any history of esophageal varices, stricture, or prior dilation of the esophagus. 3. Current use of anti-thrombotics (anti-coagulants and anti-platelet drugs) that cannot be safely discontinued for the appropriate drug-specific interval in the peri-administration period. Depending on the particular agent or reason for the anti-thrombotic therapy, it may not be necessary to discontinue anti-thrombotic agents. There could be circumstances where the drug may not need to be discontinued if the risk of bleeding is considered negligible (e.g. daily aspirin therapy). Physicians should use their clinical judgement and should consult guidelines such as those provided by the ASGE. 4. Known bleeding disorder. 5. Individuals who have had a myocardial infarction or any cardiac event \< 6 months prior to enrollment. 6. Individuals who have had a cerebrovascular event \< 6 months prior to enrollment in which swallowing was affected. 7. Prior ablative or resection therapy of the esophagus including radiofrequency ablation (RFA), photodynamic therapy (PDT), spray cryotherapy, endoscopic mucosal resection, and other ablation therapies. 8. Any history of esophageal surgery, except for uncomplicated fundoplication. 9. Do not need upper endoscopy as part of patient management. 10. Pregnancy