Esophageal Function Studies

This is a test to determine how the esophagus is working. The esophagus is the tube which carries food from your mouth to your stomach. In these studies, there is a measurement of the LES (lower esophageal sphincter) pressure. This is the pressure of the muscles at the bottom of the esophagus that keep food in your stomach. This same muscle group prevents food from returning up the esophagus. This also measures the contraction to determine whether the esophagus is working normally. In this test, other procedures including acid reflux with pH probe is done. The acid reflux with pH probe is a test which studies acid reflux, the main cause of gastroesophageal reflux (stomach acids refluxing into the lower part of the esophagus). Persons with a dysfunctional LES will reflux acid into the esophagus. This will cause a drop in pH which can be tested by a pH probe. The pH is the level of acidity or alkalinity measured in the stomach contents. Another test often done with these studies is an acid clearing test which is done to determine how many swallows it takes a patient to completely clear hydrochloric acid from the esophagus. If it takes a patient more than 10 swallows, it typically indicates the possibility of esophagitis (inflammation of the esophagus). Another test that is often performed in this series is the Bernstein test (acid perfusion). This is a test that will attempt to reproduce (cause) the symptoms of gastroesophageal reflux you have been having. If you develop pain when hydrochloric acid enters the esophagus, the test is positive and proves that the patient's symptoms are most likely caused by acid reflux. If there is no pain or discomfort, more testing may be done to determine the cause for the your symptoms.


Nothing to eat or drink for at least 8 hours prior to the test.


  • Lower esophageal sphincter pressure: 10-20 mm Hg

  • Swallowing pattern: normal peristaltic waves

  • Acid reflux: negative

  • Acid clearing: less than 10 swallows

  • Bernstein test: negative

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.


Your caregiver will go over the test results with you and discuss the importance and meaning of your results, as well as treatment options and the need for additional tests if necessary.


It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.