Inclusion Criteria:

- Aged 18 to 80

- Self-identify is "not Hispanic or Latino" and either "African American" or "White."

- Cases will be eligible for inclusion if they have endoscopically evident Barrett's
Esophagus (BE) of any length. BE will be defined as: 1) Any upward displacement of
the squamocolumnar junction noted on endoscopy such that the interface of squamous
and columnar mucosa is no longer at the interface of the most distal tubular
esophagus and the proximal gastric folds. The characteristic pale pink coloration of
the squamous epithelium in these areas will be replaced by the darker salmon color
commonly seen in BE. 2) Histologic interpretation of biopsies consistent with
intestinal columnar metaplasia containing goblet cells, which are positively stained
by Alcian blue staining as barrel-shaped cells.

- Controls will be eligible for inclusion if they have classic symptoms of
gastroesophageal reflux disease (GERD), but no endoscopic or histological evidence of
BE. Both erosive and non-erosive GERD will be eligible. Because we expect GERD to
outnumber BE and patients with GERD may be slightly less willing to participate in
the study than patients with BE (based on recruitment for the studies noted above),
we plan to randomly sample one fourth of eligible controls. If approximately 20%
fewer GERD than BE participate, a final study population with an approximately 1:2 BE
to GERD ratio will be achieved. Oversampling of patients with GERD will improve study
power.

Exclusion Criteria:

- Patients who are unable to read or comprehend the informed consent or written
questionnaires;

- Patients who are status post partial or complete esophageal resection;

- Patients with prevalent BE who have undergone endoscopic ablation;

- Patients found to have high-grade dysplasia or esophageal cancer on the index
endoscopy;

- Patients with surgical anti-reflux procedures;

- Patients of races other than Caucasian and African Americans;

- Pregnant women.

- Patients with a bleeding diathesis or other contraindication of endoscopic biopsy.

- Current use of warfarin, heparin, and/or low molecular weight heparin (requires
discontinuation of medication 5 days prior to and 7 days after EGD).