Barrett's esophagus is defined as the endoscopic finding in the distal esophagus of proximal-appearing columnar-lined esophagus of at least 1-cm length that is confirmed by histology.
It is considered a premalignant metaplastic condition that usually involves the distal esophagus.
It is postulated that exposure of the esophageal epithelium to acid damages the lining resulting in chronic esophagitis and its healing involves metaplastic process.