The esophagus is the channel leading from the throat (pharynx) to the stomach. Food travels through the esophagus to the stomach with rhythmic waves of muscular contractions called peristalsis to move the food along. Near the junction of the throat and the esophagus is a muscle called the upper esophageal sphincter. Slightly above the junction of the esophagus and the stomach is another band of muscle called the lower esophageal sphincter. When the esophagus is not in use, these sphincters contract so that food and stomach acid don't flow up from the stomach to the mouth.
A common disorder of the esophagus is heartburn, also called pyrosis or gastroesophageal reflux disease (GERD). GERD is a backflow of stomach contents upward into the esophagus. The stomach lining protects itself against the effects of its own acid, but because the esophagus lacks this protective lining, stomach acid that flows back into the esophagus can cause pain, inflammation (esophagitis), and damage.
Chronic inflammation and presence of acid in the esophagus may lead to ulcer-like tissue changes in the lining of the esophagus, called erosive esophagitis.
Barrett's esophagus is a condition indicating that there has been a change in the cell type lining the esophagus due to chronic acid exposure. These changes in the esophageal tissue may over time become precancerous or cancerous. Cancer can occur anywhere in the esophagus.
