Barrett's esophagus (BE) is a condition that often occurs in patients who have had GERD for a long time. The researchers are interested in BE because it can sometimes become a cancer in the esophagus. The way that we currently diagnose BE is by performing an upper endoscopy and looking for a change in the color of the esophagus. This color change may represent BE. If the doctor sees this, he/she may take biopsies of this area.