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.
How To Prepare
To prepare for this test:
- Do not take antacids (such as Tums or Rolaids) for 24 hours before the test.
- Follow your doctor's instructions for using other medicines 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 the test.
How It Is Done
You will be seated. You may be given a spray medicine that numbs your nose and throat. For each test, a thin, flexible tube (endoscope) will be passed through your nose or mouth to your lower esophagus and stomach. This may make you feel like you have to gag. To help overcome this feeling, focus on breathing slowly. Your pulse and blood pressure may be watched while the tube is being inserted.
- A probe that measures pH will be passed through your nose or mouth into your lower esophagus. This lets your doctor know if the pH drops because of liquid from your stomach backing up into your esophagus.
- For prolonged pH monitoring, the pH probe is attached to a small recorder. You carry the device by a strap around your waist or over your shoulder. The probe checks the pH of your esophagus for up to 24 hours while you go about your daily routines. You will need to use a diary to keep track of your activities and any symptoms you have. You may be asked to avoid high-acid foods. You will not be able to take a bath, except for a careful sponge bath, or do anything else that might get the device wet.
- For wireless pH monitoring, you will have an endoscopy procedure. A capsule that contains a pH-sensitive transmitter is placed in your esophagus. You carry a small receiver in your pocket or wear it around your waist for a certain time period. You will need to use a diary to keep track of your activities and any symptoms you have. You will press the symptom button when you have heartburn, chest pain, or regurgitation. You can bathe during the testing period. When the testing period is over, you will return the receiver and diary to your doctor for evaluation. The capsule will pass out of your body in a bowel movement, usually within a few days.
- You will swallow a small tube attached to tools called transducers that measure pressure. The tube has holes in it that sense pressure along the esophagus. It will be placed in different areas of your esophagus.
- You may be asked to swallow several times or to drink liquids while the pressure is checked.
- You may be asked to swallow, not swallow, or hold your breath during the test.
- The results are shown as a graph with a wave pattern. This helps your doctor know if your esophagus is working as it should.
If you have multichannel intraluminal impedance (MII) testing done with either pH or manometry, it will be done in very much the same ways as described above. It will measure how much food and liquid are in the esophagus as well as pH or pressure.
How It Feels
The local anesthetic sprayed into your nose and throat usually tastes slightly bitter. It will make your tongue and throat feel numb and swollen.
When the tube goes through your nose or mouth into your esophagus, you may feel like coughing or gagging. The test may be easier if you try to take slow, deep breaths. You may not like the taste of the lubricant on the tube.
If you have a test that involves adding acid to your stomach, you may have heartburn pain and other symptoms of acid reflux.
If you have the wireless pH monitoring, you may be able to feel the capsule in your esophagus. You will not feel the capsule when it detaches and passes through your intestines and out of your body in your stool.
After the test is over, your nose and throat may feel sore. But this should improve within a day or so.
The chances that you will have problems from an esophagus test are rare.
- You may get a nosebleed.
- You may have irregular heartbeats (arrhythmias).
- The tube may go down the windpipe (trachea) instead of the esophagus as it is being inserted.
- You may vomit material from your stomach and then breathe it into your lungs (aspiration).
- The tube may make a hole in the esophagus.
You can usually get your results within a few days.
Many conditions can affect the results of these tests. Your doctor will discuss your results with you in relation to your symptoms and past health.
Current as of: February 28, 2023
Author: Healthwise Staff
Clinical Review Board: All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.