Esophageal pH test and monitoring measures acidity in the esophagus
An esophageal pH monitor measures the acidity inside of the esophagus. It is helpful in evaluating gastroesophageal reflux disease (GERD). A thin, plastic tube is placed into a nostril, guided down the throat, and then into the esophagus. The tube stops just above the lower esophageal sphincter, which is the connection between the esophagus and the stomach. At the end of the tube inside the esophagus is a sensor that measures pH, or acidity. The other end of the tube outside the body is connected to a monitor that records the pH levels for a 24- to 48-hour period. The test measures how often stomach acid refluxes (flows back) into the lower esophagus and the degree of acidity over a period of time.
Normal activity is encouraged during the study, and a diary is kept of symptoms experienced, or activity that might be suspicious for reflux, such as gagging or coughing, and any food intake by the patient. It is also recommended to keep a record of the time, type, and amount of food eaten. The pH readings are evaluated and compared to the patient's activity for that period.
24-hour esophageal pH and impedance monitoring
Esophageal impedance monitoring is used to evaluate reflux of digestive fluids other than stomach acid, such as bile. Impedance testing is helpful when determining the cause of reflux symptoms. We offer a 24-hour test that monitors for both acid and nonacid secretions. For the test, a thin flexible tube with a tiny monitoring device at the end is inserted into the nose and guided into the esophagus. The tube is removed the following day.
48-hour esophageal pH monitoring
With this test (also called a Bravo test), a capsule-sized acid-measuring probe is attached to the lower part of the esophagus during an upper endoscopy procedure. Over the next 48 hours, a monitoring device is worn that captures information from the probe. The probe then detaches and is excreted in a bowel movement.