The esophagus is the muscular tube that conveys food from the
back of the throat to the stomach. It is located in the chest
behind the sternum and the trachea, the main breathing tube
leading to the lungs. The esophagus joins the stomach at the
diaphragm, which is the breathing muscle separating the chest
and lungs from the abdomen. The connection of the esophagus to
the stomach at the diaphragm is called the gastro-esophageal
junction. The gastro-esophageal junction serves as a one-way
valve to keep stomach contents from being refluxed or
regurgitated back into the esophagus. Once food has emptied into
the stomach, it is mixed with enzymes and acids from the stomach
and gall bladder to enhance digestion. If stomach contents
reflux or regurgitate back into the esophagus the surface lining
can be damaged due to the acidity of these contents. One symptom
of regurgitation of stomach contents into the lower esophagus is
heartburn, which is a common condition occurring in
approximately 10% of all people. Heartburn