Esophageal pH/Impedance Testing |… | Cary Gastroenterology Associates

This test measures how often stomach acid refluxes up into the lower esophagus. A thin, flexible tube with sensors is gently inserted through a nostril into your esophagus, and then connected to a portable pH monitor. You will wear the monitor for 24 hours while it measures the acid content of your esophagus, recording frequency and length of reflux episodes as you go about your normal daily activities. One of our gastroenterology specialists then evaluates the recording.


  • Please do not eat or drink anything for at least six hours before the test
  • Consult with your doctor if you take any regular medication, as many must be discontinued for at least 24 hours before your appointment
  • Wear comfortable clothing, and consider that a shirt or blouse that buttons in the front may be easier to change during the 24-hour monitoring period

Esophageal pH Test Patient Information

What To Expect

The monitor insertion process takes about ten minutes. You will have to wear the tube taped to your nose and face for 24 hours, so you may want to plan any social activities accordingly. You may feel some discomfort in your chest when swallowing, which is normal as food or esophageal contraction tugs on the sensor as is passes. To protect the recorder, you may not shower or take a bath during the 24-hour test period. Immediately after the tube is removed, you may resume your usual diet, activities, and medication(s).


There are no significant risks related to an esophageal pH monitoring test.

Your Health Matters

Book an appointment today at one of our office locations throughout the Cary, Raleigh, Holly Springs and Triangle region. We are committed to providing you with the most comprehensive quality of gastroenterology care.