pH Probe

An esophageal pH monitor measures the acid levels inside of the esophagus to test for gastroesophageal reflux disease in younger children.

  • A thin plastic tube (catheter) 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 at the connection between the esophagus and the stomach.
  • At the end of the tube inside the esophagus is a sensor that measures pH.
  • The other end of the tube outside the body is connected to a monitor that records the pH levels for 24 hours. 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.
  • The pH readings are evaluated and compared to the child's activity for that time period.