This study will assess the Minimally Invasive Esophageal Cytology Collection System in Patients with Barrett's Esophagus or GERD Symptoms.

This is a cross-sectional study of subjects with Barrett's esophagus (BE) to assess the utility of the Cytosponge device as a non-endoscopic method for collecting surface cells from the esophagus. This study will enroll 2 groups of subjects: 1) Subjects presenting for routine endoscopic BE surveillance examinations (n=120), and 2) Subjects with gastroesophageal reflux disease (GERD) symptoms undergoing upper endoscopy for screening for BE (n=55). After informed consent, and on the same day as the endoscopic procedure, the subject will undergo administration of the Cytosponge device and complete a questionnaire. The subject will then undergo routine upper endoscopy, with assessment of BE (where applicable), and biopsy per accepted surveillance or screening recommendations. The Cytosponge will be placed in fixative and shipped to an accredited pathology laboratory for embedding in paraffin and hematoxylin and eosin (H&E) staining to assess the adequacy of the specimen. Further evaluation of the specimen may be performed using trefoil factor 3 (TFF3). If the Cytosponge tissue specimen is inadequate, the subject will be recalled for a repeat sponge procedure (not endoscopy) 30 days later. Routine care tissue biopsies will undergo standard processing and H&E staining at the home institution, with assessment by expert gastrointestinal pathologists. Subjects will be contacted via phone 7 days (+/- 2 days) after Cytosponge administration to complete additional questionnaires and assess adverse events.

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

Subjects will be contacted 7 days (+/- 2 days) following the Cytosponge and upper endoscopy procedures. During this phone call, adverse events will be assessed and subjects will complete questionnaires. Participation in the study is complete when subjects have completed the follow-up phone call.