24-Hour pH Testing: Measuring Acid Reflux

Ambulatory pH testing measures how often stomach contents reflux into the esophagus over 24 hours or longer, and whether reflux lines up with your symptoms. It's the most accurate way to confirm GERD.

Why it's done

• Heartburn or regurgitation that doesn't improve with medicine
• Unusual symptoms such as chronic cough, hoarseness, or chest pain
• Before reflux surgery or endoscopic reflux procedures
• To decide whether long-term acid medicine is truly needed

Types of tests

• Catheter test: a thin tube through the nose connects to a small recorder for 24 hours. Impedance sensors can also detect non-acid reflux.
• Wireless capsule (such as Bravo): a small capsule is attached to the esophagus during an upper endoscopy and records for 2 to 4 days. It falls off and passes on its own.

How to prepare

• You may need to stop acid-reducing medicine for about a week. Your doctor will tell you whether to test on or off medicine.
• Don't eat or drink for several hours before placement. Our team will give you exact instructions.

During the test

Eat, work, and sleep as usual, and record meals, lying down, and symptoms in a diary or by pressing buttons on the recorder. Avoid changing your routine, so the results reflect a typical day.

Your gastroenterologist reviews the results with you and recommends treatment based on them.

Make an appointment

Our gastroenterologists in Temple City care for patients from Arcadia, San Gabriel, Pasadena, Monrovia, Monterey Park, and across the San Gabriel Valley. We accept most PPO plans (see accepted insurances), and our doctors speak English, Vietnamese, and Mandarin. Schedule an appointment or call 626-898-4560.

This article is for general education and is not a substitute for medical advice. Talk with your doctor about your own health.