Esophageal Function Tests The esophagus is the swallowing tube
through which food passes on its way from the mouth to the
stomach. The main function of this organ is to propel food down
into the stomach. There is also a mechanism to prevent food from
coming back up or "refluxing" from the stomach into the
esophagus. Esophageal function tests are used to determine if
these processes are normal or abnormal. The esophagus is a long,
muscular tube that also has two muscles (or sphincters) at the
top and bottom. All of these muscular areas must contract in an
exact sequence for swallowing to proceed normally. There are
three main symptoms that occur when esophageal function is
abnormal: difficulty with swallowing (dysphagia), heart-burn,
and chest pain. Doctors perform a variety of tests to evaluate
these symptoms. Endoscopy, which is not a test of esophageal
function, is often used to determine if the lining of the
esophagus has any ulcers, tumors, or areas of narrowing
(strictures). Many times, however, endoscop