This study is being done to:

Determine if a temporary dye applied to the esophagus identifies areas of dysplasia (pre-cancer). Determine if certain dye patterns indicate specific grades of dysplasia. Determine if overall endoscopy costs can be reduced with this dye technique. Determine if the dye could allow fewer biopsies to be obtained in the future.

Although methylene blue has been used effectively to identify areas of SIM in several studies, its superiority in identifying dysplasia in the setting of Barrett's esophagus has been inconclusive. In all studies to date dysplastic yield was equivalent or better than protocol techniques while requiring fewer biopsies. Variations in study design, staining technique and inexperience in staining interpretation are some of the reasons. Our goal is to build on the techniques that have been shown to be effective, standardize them for the purposes of our study, and to objectively evaluate if MB directed biopsies are useful in screening Barrett's patients for dysplasia. At the time of EGD when length of Barrett's is determined, patients will be stratified into either intermediate (2-4cm) or long segment (>4cm) Barrett's. Short segment Barrett's esophagus patients will not be considered, as MB techniques have not proved beneficial in dysplasia detection as previously described 7.

Inclusion Criteria:

• History of Barrett's with or without dysplasia
• Able to give consent

Exclusion Criteria:

• Pregnancy or women of child-bearing potential
• Active esophagitis
• Esophageal varices
• Esophageal cancer (history of or current)
• Hypersensitivity to methylene blue
• Severe renal impairment (creatinine>2.0)
• Known glucose-6-phosphate dehydrogenase (G-6-PD) deficiency
• Symptomatic coronary artery disease
• Coagulopathy (INR>/=1.5)
• Thrombocytopenia \

Patients presenting for surveillance upper endoscopy to assess Barrett's esophagus.