Esophageal manometry is a test to measure the pressure inside the lower part of the esophagus.

When you swallow, muscles in your esophagus contract to help push food toward your stomach. Valves, or sphincters, inside the esophagus open to let food and liquid through, and then close to prevent food, fluids, and gastric acid from moving backward. The sphincter at the bottom of the esophagus is called the lower esophageal sphincter or LES.

During esophageal manometry, a thin, pressure-sensitive tube is passed through your mouth or nose and into your stomach. Once in place, the tube is pulled slowly back into the esophagus.

When the tube is in the esophagus, you will be asked to swallow. The pressure of the muscle contractions will be measured along several sections of the tube.

While the tube is in place, other studies of your esophagus may be done. The tube is removed after the tests are completed. The test takes about 1 hour.

You should not have anything to eat or drink for 8 hours before the test.

You may have a gagging sensation and some discomfort when the tube is put into place.