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.
- Tell your doctor if you have any other problems, such as enlarged esophageal blood vessels, heart failure, or other heart conditions.
Talk to your doctor about any concerns you have about 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?).
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.