The cells lining the stomach and intestines are different than the cells lining the esophagus. The cells lining the stomach need to protect the stomach from acid. The cells of the esophagus do not need to protect the esophagus from acid. If there is reflux of acid into the esophagus, the esophagus may try to protect itself over time by developing cells similar to the intestine. When these types of cells occur, Barrett's Esophagus is diagnosed. These intestine cells may show abnormal changes or dysplasia over time. This is a concern because over time dysplasia (low grade, then high grade dysplasia) can develop into cancer of the esophagus.
Gastroesophageal reflux disease (GERD) is the most common cause of Barrett's Esophagus, but Barrett's Esophagus can also be seen at birth, although this is not very common. Barrett's Esophagus tends to be seen more often in men than women.
GERD is a backward flow or reflux of stomach contents into the esophagus. The esophagus is the tube from the mouth to the stomach. Everybody has some reflux. Abnormal amounts of gastroesophageal reflux can cause GERD. This can occur when the valve of smooth muscle between the esophagus and the stomach does not function properly. This muscle band is called the lower esophageal sphincter. Learn more about GERD.