Digestive Disorders Health Center

Esophagus tests measure muscle pressure and movement, coordination, and strength of the tube that connects the throat to the stomach (esophagus). They test how well the ring of muscles (sphincters) at the top and bottom of the esophagus work. Esophagus tests also measure the movement and volume of gas, liquid, and solid through the esophagus and its pH (acid or non-acid). See a picture of the esophagus .

The most common esophagus tests include:

• pH monitoring (esophageal acidity test), which measures the acid content (pH) in the esophagus. A low pH for long periods may mean frequent abnormal backflow (reflux) of stomach acid into the esophagus (gastroesophageal reflux disease, or GERD).
• Esophageal manometry, which measures the strength and pattern of muscle contractions in the esophagus. This test can find:
  • Weakness in the lower esophageal sphincter (LES), which allows acid to reflux into the esophagus.
  • Weak muscle contractions during swallowing that slow the rate at which food or stomach acid is cleared from the esophagus.
  • Abnormally strong contractions (spasms) that can cause chest pain or the sensation that food is stuck after swallowing (dysphagia).

Either pH or manometry testing can be combined with a test that measures the movement and volume of gas, liquid, and solid through the esophagus (multichannel intraluminal impedance testing, or MII). When MII is combined with manometry (MII-EM), it can show how the muscles of the esophagus are contracting when there is food or liquid in the esophagus. When MII is combined with pH testing (MII-pH), it can detect reflux from the stomach into the esophagus and measure both the volume and the acidity.

Why It Is Done

Tests on the esophagus are done to:

• Help find the cause of chest pain that is not caused by heart problems (called noncardiac chest pain).
• Help determine the cause of GERD symptoms for a person who has not been helped by medicine and whose esophagus looks normal during an endoscopy test.
• Monitor the effectiveness of treatment for GERD.
• Detect spasms of the esophagus, which can cause chest pain, and problems with the ability of the esophagus to move food down to the stomach (motility problems).
• Determine whether the esophagus is working normally.
• To evaluate how the esophagus works before surgery for GERD.

Esophagus tests are usually not done in people with GERD if their symptoms are well controlled with medicine.

How To Prepare

To prepare for an esophagus test:

• Do not take antacids (such as Tums or Rolaids) for 24 hours before the test.
• Follow your doctors instructions for using other acid reducers or blockers, such as famotidine (Pepcid) or omeprazole (Prilosec), before the test.
• Do not drink alcohol or smoke for 24 hours before the test.
• Do not eat or drink for 8 to 12 hours before testing.
• Tell your doctor if you have any other problems, such as enlarged esophageal blood vessels (esophageal varices), heart failure, or other heart conditions.

Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results may mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).