Barrett's esophagus, a precursor to esophageal adenocarcinoma, is a condition in which the normal squamous lining of the esophagus is damaged by gastric acid and replaced by metaplastic columnar cells. These cells change the color of the esophagus from pale-pink to a deep pink/ red. Prevention of acid reflux is the key to prevent its development. This includes avoidance of risk factors such as obesity, stress, smoking, and use of agents which suppress gastric acid in the susceptible population.