Ambulatory pH Monitoring By Jonathan Gotfried, MD, Lewis Katz School of Medicine at Temple University Reviewed / Revised Mar 2023 View Patient Education Catheter-Based pH Monitoring Wireless pH Monitoring More Information Ambulatory 24-hour esophageal pH monitoring with or without intraluminal impedance testing is currently the most common test for quantifying gastroesophageal reflux (see the American College of Gastroenterology's 2022 Clinical Guideline for the Diagnosis and Management of Gastroesophageal Reflux Disease).