A wireless capsule is temporarily attached to inside wall of the esophagus to monitor the extent of acid refluxing from the stomach. This test is performed to help diagnose the severity of GERD symptoms. The capsule transmits the gathered data to a small recording device worn on a belt.


It is important to follow your doctor’s specific instructions prior to the scheduled exam. If the test is being used to diagnose GERD, you will be asked to cease taking any prescription or over the counter heartburn medicine. If this test is being used to determine a medication’s effectiveness in treating GERD, you will continue your normal medication routine as directed. Your doctor’s instructions will be complete for your individual needs.

The Test

After the capsule is attached, the patient is will go about their day as usual. The point is to recreate the situations that cause symptoms. Eating regular meals, including foods that may cause heartburn, and sleeping as part of a normal day are all important components of the test. There are buttons on the recording device to press when symptoms occur. Patients are also asked to record the times of eating and drinking, as well as lying down. This data is compared to the changes in pH recorded by the capsule to get a more complete picture of the acid reflux.

After the 48 hours have passed, the recorder is returned to the doctor’s office. The data can then be analyzed and the results used to confirm a GERD diagnosis or, in some cases, verify the effectiveness of medicines.

After The Test

After the testing period is complete, returning to your normal diet will dislodge the capsule and harmlessly pass through the digestive tract. This takes an average of 7-10 days. Thirty days after the initial attachment, the patient should not have any MRI exams.

Before your visit, please view the patient forms available online.

48-Hour pH Probe Procedure and General Patient Forms