Barrett's esophagus is a condition in which the lining of the esophagus is replaced by abnormal cells. The esophagus is the tube that connects the throat to the stomach. Barrett's esophagus is a precancerous condition.

What is going on in the body?

The esophagus is connected to the stomach by the esophageal sphincter. This is a muscular ring. Normally, this muscle performs two major functions. It opens to allow food to pass into the stomach. It also closes to keep the contents of the stomach from splashing back up into the esophagus.

If this sphincter weakens or relaxes, the contents of the stomach splash back up into the esophagus. This splashing is known as gastroesophageal reflux disease, or GERD. The lining of the esophagus is not made for this kind of abuse. After being exposed to stomach acid over a long period of time, the lining of the esophagus changes. This change in the lining of the lower esophagus is called Barrett's esophagus.

Sometimes the damaged cells lining the esophagus cause narrowing of the opening. This narrowing of the esophagus is known as an esophageal stricture. A person with this condition will have trouble swallowing food and liquids.

What are the causes and risks of the condition?

GERD is the major cause of Barrett's esophagus. Esophagitis, or chronic inflammation of the esophagus, can also lead to Barrett's esophagus. One-third of all people with scleroderma, a skin disorder, develop Barrett's esophagus. For some unknown reason, Barrett's esophagus occurs three times more often in males than in females. It is seen mainly in white men who are 40 to 50 years of age.

GERD can be caused by a weak esophageal sphincter that is present at birth or develops later in life. A hiatal hernia can also cause GERD. Hiatal hernia is a condition in which the stomach pushes up into the diaphragm muscle. When this happens, the esophageal sphincter does not work properly. As a result, the fluid can easily leak back into the esophagus.

Factors that make GERD worse include the following: