pH Impedance Testing/ Esophageal pH Monitoring

pH impedance testing, also called esophageal pH monitoring or 24-hour ambulatory reflux monitoring, is the gold standard for diagnosing gastroesophageal reflux disease (GERD). The test records both acidic and nonacidic reflux episodes inside the esophagus during a 24-hour period. Specifically, it measures how much stomach acid backs up into the esophagus and how long it stays there. It also measures the strength of your stomach acid.

How to Prepare for pH Impedance Testing

Do not eat or drink anything 6 hours prior to the procedure. Your doctor will let you know if or when you should adjust or stop any medications you take.

What to Expect for Esophageal pH Monitoring

The provider will insert a thin, flexible, disposable probe (the size of a spaghetti noodle) through the nose and throat into the esophagus. The probe is then securely taped to the nose and cheek with the other end connected to the pH monitoring device.

The monitor is then placed inside a pouch that you will wear at waist level, held by a strap over your shoulder, for 24 hours. You will be instructed how to use the monitor to record symptoms, meals, and sleep.

The probe is removed the following day. The data is then downloaded for analysis and diagnosis by the interpreting physician.

Even though the tube is visible, you are encouraged to go about your regular activities, such as work and eating your normal diet, including those foods that provoke your symptoms.