Your esophagus is the tube that connects your throat to your stomach. It moves food and liquid down to the stomach. Esophagus tests can check how well the muscles in the tube work, how strong the tube is, and the pH (acid content) of the tube. They also can find out how much gas, liquid, and solid move through the esophagus and how well they pass through.
The most common tests include:
pH monitoring (acidity test). This checks the acid content (pH) in the esophagus. A low pH for long periods may mean that you often have abnormal backflow (reflux) of stomach acid into the esophagus (gastroesophageal reflux disease, or GERD).
Esophageal manometry. This checks the strength and pattern of muscle contractions in the esophagus. This test can find:
- A weak lower esophageal sphincter. This may cause reflux.
- Weak muscle contractions when you swallow. This could slow the rate at which food or stomach acid is cleared from the esophagus.
- Very strong contractions (spasms) that can cause chest pain. Or they can make you feel that food is stuck after you swallow (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. This test is called a multichannel intraluminal impedance test, or MII. When MII is combined with manometry, it's called 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, it's called MII-pH. It can detect reflux from the stomach into the esophagus and measure both how much reflux there is and how acidic it is.
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.
- Help find the cause of GERD symptoms if you have not been helped by medicine and your esophagus looks normal during an endoscopy test.
- Check how well GERD treatment is working.
- Detect spasms of the esophagus. Spasms can cause chest pain and problems with how food moves down to the stomach.
- Find out if the esophagus is working as it should.
- Check how the esophagus works before surgery for GERD.
These tests are usually not done if you have GERD and your symptoms are well controlled with medicine.