24-Hour pH/Impedance Test

What is a 24-Hour pH/Impedance Test?

Patients with chronic heartburn or other suspicions for gastroesophageal reflux disease (GERD) may be asked to undergo a 24-hour pH/Impedance test. This exam quantitatively measures the amount and chemical nature of reflux episodes during a twenty-four hour period. It can help differentiate between different types of esophageal reflux episodes (acid vs non-acid). The test also allows your doctor to correlate your symptom(s) to those episodes of reflux for better symptom management.

What is involved with this test?

The test is performed in our office and is usually performed in conjunction with an esophageal manometry study. Your doctor will anesthetize (numb up) your nose and throat, and then pass a very thin catheter (tube) through one nostril into your esophagus. This catheter will be connected to a computer recorder which will record and analyze any episodes of esophageal reflux during the 24-hour test duration. You will need to return to our office the following day to have the catheter and recorder removed. You do not need to fast for the removal process, which generally takes about a minute.

During the study, most patients will be allowed to eat and drink normally. Most activities can be performed, but you will not be allowed to shower or otherwise get the equipment wet. Please be aware that the catheter will be visible during the test.

Preparing for the procedure

You should not eat or drink for four hours before the 24-hour pH/Impedance test. Some patients, but not all patients, will be asked to stop taking acid suppression or antacid medications several days before this study and during it; please clarify this with your doctor in advance so that we can obtain the most useful study results for you.

What can I expect during and after the 24-Hour pH/Impedance test?

Most people only experience minimal side effects during or after a 24-hour pH/Impedance test. You may have a sore throat or stuffy nose, but both should resolve within a few hours. The use of throat lozenges, especially those containing a topical anesthetic like lidocaine or benzocaine, can improve your comfort during the test and will not interfere with the results. Minor nosebleeds may also occur.