24-Hour pH-Metry for Gastroesophageal Reflux Disease (GERD) Evaluation

What is 24-Hour pH-Metry?

24-hour pH-metry is a test that measures how often stomach acid flows back into your esophagus (the tube connecting your mouth to your stomach) and how long it stays there. It helps diagnose GERD, a condition where stomach acid causes symptoms like heartburn, regurgitation, chest pain, or throat issues. It can also check if your GERD treatment is working or evaluate symptoms not explained by other tests.

Why is this test done?

Your doctor may recommend this test if:

• You have heartburn, regurgitation, or other GERD symptoms that don’t improve with medications (e.g., proton pump inhibitors or PPIs).

• You have atypical symptoms like chronic cough, hoarseness, sore throat, asthma, or chest pain that might be related to GERD.

• You’re being considered for anti-reflux surgery.

  

How does the test work?

The test uses a thin, flexible tube (catheter) or a wireless capsule to measure acid levels (pH) in your esophagus over 24 hours. The two main methods are:

1. Catheter-based pH monitoring: A small tube with a pH sensor is inserted through your nose into your esophagus. It’s connected to a small recording device you wear on a belt or shoulder strap.

2. Wireless pH monitoring (e.g., Bravo system): A small capsule is attached to your esophagus during an endoscopy. It sends pH data to a recorder you wear, and the capsule detaches after a few days, passing naturally through your digestive system.

The test records acid reflux episodes (when esophageal pH drops below 4) and correlates them with symptoms you log in a diary (e.g., heartburn, coughing).

How to prepare for the test

Your doctor will provide specific instructions, but general guidelines include:

• Medications: You may need to stop certain medications, such as PPIs (e.g., omeprazole, esomeprazole) or H2 blockers (e.g., ranitidine), 1–14 days before the test, as they can affect results. Do not stop any medication without your doctor’s approval.

• Fasting: Avoid eating or drinking anything for 4–8 hours before the test. If you’re diabetic, discuss fasting with your doctor.

• Clothing: Wear loose, comfortable clothing, preferably a button-up shirt.

• Inform your doctor: Tell your doctor about all medications, allergies, or medical conditions (e.g., nasal issues, bleeding disorders).

What to expect during the test

• Catheter placement : A technician will insert a thin tube through your nose into your esophagus, which takes about 10 minutes. You may feel brief gagging or discomfort, but no sedation is needed. The tube is taped to your cheek and connected to a recorder.

• During the 24 hours:

  • Carry the recorder on a belt or strap and keep a diary of symptoms (e.g., heartburn, cough), meals, and sleep times. Press buttons on the recorder to mark symptoms as instructed.

  • Follow your normal routine, including eating regular meals, to get accurate results. Avoid acidic drinks (e.g., fruit juice, soda, alcohol) unless told otherwise.

  • You cannot shower or bathe during the test to avoid damaging the equipment. Be careful around pets or small children to prevent pulling the catheter (if used).

• After 24 hours: Return to the clinic to have the catheter removed (takes 1–10 minutes) or return the recorder (for wireless systems). The data will be analyzed to assess acid reflux and symptom correlation.

What are the risks?

The test is very safe, but possible side effects include:

• Mild discomfort in the nose or throat (catheter-based method).

• Rarely, nosebleeds or irritation from the catheter.

• For wireless capsules, rare issues include the capsule not staying in place or causing discomfort.

• No major complications are typically reported.

What do the results mean?

Your doctor will review the data to determine:

• Acid exposure: How often and how long acid refluxes into your esophagus. A DeMeester score (a composite measure of reflux) above 14.72 often indicates GERD.

• Symptom correlation: Whether your symptoms (e.g., heartburn, cough) match reflux episodes, using indices like the Symptom Index (SI) or Symptom Association Probability (SAP).

• Treatment planning: Results help decide if lifestyle changes, medications, or surgery are needed. If no acid reflux is found, your doctor may explore other causes for your symptoms.

After the test

• You can resume normal activities and medications unless told otherwise.

• Your doctor will discuss results and next steps, which may include dietary changes, medications (e.g., PPIs, antacids), or further tests.

• If GERD is confirmed, treatment may prevent complications like Barrett’s esophagus or esophageal damage.

Questions to ask your doctor

• How long will I need to stop my medications before the test?

• How will the results affect my treatment plan?

• What should I do if I feel discomfort during the test?

For more information or to schedule the test, contact your healthcare provider.