The goal of the project is to determine whether confocal endomicroscopy can be used to identify and discriminate among dysplastic, neoplastic, and nonneoplastic tissue, as compared with histologic specimens as a reference. The project will evaluate those at risk for or with known Barrett's esophagus, and those with known or suspected biliary strictures. It is our hypothesis that we will be able to identify between neoplastic and nonneoplastic tissue.

This study was amended from it's initial design to increase the number of patients to 200. The study was terminated in July 2016 after 106 patients were enrolled and had completed the study.

Inclusion Criteria:

• Patients with long-standing reflux symptoms, undergoing surveillance for Barrett's esophagus, or scheduled for endoscopic therapy with esophageal dysplasia
• Patients undergoing ERCP for known or suspected biliary strictures.

Exclusion Criteria:

• have a known allergy or have had a prior adverse reaction to fluorescent contrast agents or chromoendoscopy stains
• are younger than age 18 or who are mentally or legally incapacitated or unable to give informed consent
• are pregnant or breastfeeding
• patients with advanced esophageal cancer
• acute gastrointestinal bleeding
• coagulopathy
• impaired renal function

Patients with long-standing reflux symptoms, undergoing surveillance for Barrett's esophagus, or scheduled for endoscopic therapy with esophageal dysplasia. Also, patients undergoing ERCP for known or suspected biliary strictures.