Your child's pediatric gastroenterology specialist may order a pH Study to test for the reflux of stomach acid into the esophagus. These include the pH Probe, BRAVO Probe and Impedance Probe studies. The tests are used when the pediatric gastroenterologist suspects the child's problem to be eosinophilic disorders or GERD. The information from these tests will be helpful in making the correct diagnosis.

These procedures help examine for reflux of stomach acid into the esophagus.

pH Probe

A small plastic tube will be passed through the nose and into the esophagus. At the end of the tube sensors that detect acid reflux will be positioned at specific spots along the esophagus. Placing the tube only takes a few minutes and can be done in clinic without sedation, though some children may have the pH probe placed in the endoscopy suite while under general anesthesia if the test is done in coordination with Upper GI endoscopy. The probe will remain in place for 24-26 hours and record the occurrence of acid reflux on a small recorder worn by the child.

Impedance Probe

This test is used to detect both acid and non-acid reflux. A small plastic tube will be passed through the nose and into the esophagus. At the end of the tube sensors will be positioned at specific spots along the esophagus. Placing the tube only takes a few minutes and can be done in clinic without sedation, though some children may have the pH probe placed in the endoscopy suite while under general anesthesia if the test is done in coordination with Upper GI endoscopy. The probe will remain in place for 24-26 hours and record the occurrence of acid and non-acid reflux on a small recorder worn by the child.

Bravo Probe

This test is similar to the esophageal pH probes except it uses a small capsule rather than a long tube and is done only in the endoscopy suite in conjunction with an Upper GI endoscopy. The capsule is attached to the lining of the esophageal wall and sends data on acid reflux, by wireless technique, to a small recorder that the child will wear. The recording lasts for 48 hours and you will need to bring back the recorder to our office. The capsule will fall off of the esophagus after a few days and pass out in stool. You should not try to retrieve the capsule from the stool. If you have not seen the capsule pass after two weeks, the physician may use a chest x-ray to ensure that the capsule has detached from the esophagus.

The advantages of the Bravo test over the esophageal pH probes are:

1. there is no tube sticking out of the child's nose
2. the child does not feel the presence of the capsule

The Bravo test is generally not done under the age of four years as there is a risk that the capsule may get stuck in the GI tract.