Impedance and pH Study for Adults Make an Appointment Ask a Question Refer Patient What is an impedance and pH study? How do you get ready for the test? What is done during the test? How long will the test take? How do you get to your test? What is an impedance and pH study? This test measures how much acid reflux and non-acid reflux you have. Everyone has some reflux from their stomach into their esophagus. This test will determine whether the amount of reflux you have is abnormal. How do you get ready for the impedance and pH study? Do not eat food or drink liquids for at least two hours before the test Do take any reflux/antacid medicines as your doctor has prescribed Do continue all your other medicines as you usually do. What is done during the test? The impedance probe is a long thin tube that is inserted into your nose and down into your stomach. Before the probe is inserted, the nurse will squirt medicine into your nose that makes your sinuses slippery and helps diminish your discomfort. The probe will be mildly uncomfortable during insertion, and this is normal. Brief, mild gagging is also common. Once the probe is placed in its final position, the nurse will tape it to your nose, face and neck. You will feel the probe in your throat for the duration of the study. A mild sore throat is common. The probe is attached to a recorder, which you will take home with you. The nurse will explain the proper use of the recorder. You will also go home with a journal. The nurse will explain the proper use of the journal. This test attempts to capture a “normal” day in your life, so try to maintain all regular activities (eating, exercise, sleep, etc) as much as possible. How long will the impedance and pH study take? The probe needs to be in for 22 hours. The nurse will provide you the time and place your probe can be removed the next day. How do you get to your test? One the day of your scheduled test, check in at the front desk in the adult clinic. If you have questions before or during your test, please call 303.270.2424. If you need to cancel or reschedule your appointment, please call 303.398.1355. Get directions and see a campus map of National Jewish Health.