What is a 24-Hour pH / Impedance Test?

Patients with chronic heartburn or other suspicions for gastroesophageal reflux disease (GORD) may be asked to undergo a 24-hour pH/Impedance test. This examination quantitatively measures the amount and chemical nature of reflux episodes during a twenty-four hour period. It can help differentiate between different types of oesophageal 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 clinical unit MGIU, Suite 35, Cabrini Medical Centre (map) in conjunction with an oesophageal manometry study. We will anaesthetise (numb) 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 analyse any episodes of oesophageal 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. Most patients, but not all patients, will be asked to stop taking acid suppression or antacid medications a week before this .

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. 

Patient Information

Handy resources to make your preparation and admission as easy as possible.