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24-Hour pH Study

How to Prepare | What to Expect On Arrival | What to Expect After | For More Information

A 24-Hour Esophageal pH Study is performed to evaluate the amount of stomach acid washing up into the esophagus over the course of a 24-hour period. Your physician may recommend this stomach acid test if you have heartburn or other stomach problems, or as a pre-operative test before acid reflux surgery. 

Occasionally, esophageal pH monitoring is suggested for patients with atypical reflux symptoms (zero to very little to heartburn) to diagnose the cause of pulmonary problems such as asthma or chronic coughing or throat complaints such as hoarseness and laryngitis. The test helps to determine if acid reflux is a potential contributor to these conditions.

This test often immediately follows esophageal manometry.

How to prepare for the 24-Hour Esophageal pH Monitoring

7 days prior to the test:
The following medications should be stopped: Prilosec (omeprazole), Prevacid (lansoprazole), Protonix (pantoprazole) and Aciphex (rabeprazole). Occasionally, under special doctor’s instructions, these medications are continued through the testing period for specific reasons. 

2 days prior to the test:
The following medications should be stopped prior to the stomach acid test: anti-ulcer or antacid medications (i.e., Tagamet, Pepcid and Zantac).

1 day prior to the test:
The following medication should be stopped: Reglan (metoclopramide).

12 hours prior to test:
The following medications should be stopped with your physician’s approval: nitrobid, nitropaste, nitroglycerine patches, verapamil, cardizem and nifedipine.

No food or liquid (includes water) after midnight the night before the test. 

What to expect once you arrive for your 24-Hour Esophageal pH Monitoring

  • A topical anesthetic is sprayed into the nose.
  • A thin flexible wire is passed through the nose and positioned into the lower esophagus.
  • There is no sedation given during the test.
  • This wire has small acid sensors built into the tip of the tube. The other end of the wire is connected to a small computer that is worn by the patient.
  • The patient is asked to wear the acid sensor for 24 hours. The computer records the amount of acid coming up from the stomach into the esophagus.

What to expect after the 24-Hour Esophageal pH Monitoring

  • The patient returns the next day to have the wire and the computer removed. The wire and the computer take about 30 minutes to set up and about 5 minutes to remove.

For More Information

The 24-Hour esophageal pH monitoring is available at our Highland Park GI Lab. For more information or to schedule an appointment, please call 847.480.2828.

NorthShore offers interpretive language services for non-English speaking patients. A request for this no-cost service should be made at the time of appointment scheduling.