Esophageal pH monitoring is performed if you are having problems with your upper digestive tract. It helps your doctor determine if stomach acid is entering the esophagus.
The esophagus is the muscular tube that connects your throat to your stomach. It is lined with a soft mucous membrane. The membrane protects it from damage.
The esophagus plays a very simple role in the digestive process. It conveys food from the throat to the stomach. This is the very start of your digestive system. Therefore, it is frequently exposed to sharp or abrasive food items like:
- shards of bone
- tough plant leaves
- potato chips
Why Might You Need This Test?
You doctor may recommend this test if you have symptoms of GERD (gastroesophageal reflux disease). The test measures how often and for what length of time acid enters the esophagus.
GERD is a chronic disease of the digestive system caused by bile or acid backing up from your stomach. This causes the following symptoms:
- heartburn (acid indigestion in your stomach, chest, or abdomen)
- regurgitation (discomfort from acid backing up into your throat or mouth)
- dyspepsia (burping, bloating, or nausea after eating)
Many people experience these symptoms from time to time. GERD may be suspected if you are experiencing them more than twice each week.
Your doctor may also want to test you if symptoms are so severe that they interfere with your daily life.
This test may be performed in combination with an endoscopy of the upper gastrointestinal (GI) tract. Endoscopy inserts a camera into your esophagus to look for causes of GERD.
In infants, this test can also be used to check for digestive disorders that could cause excessive crying.
How the Test Is Administered?
Your doctor will pass a fine tube down your throat into your esophagus. At the end of the tube is a tiny pH meter. It calculates the amount of acid present.
You will return home with the tube in place. For the next 24 hours, you will make notes of:
- what time you eat and drink
- what food you eat and drink
- what time you lie down or get up
- any symptoms you experience
The following day, you will return to the hospital to have the tube removed. Data from the device will be combined with your notes to make a diagnosis.
Children are usually required to stay in hospital for the whole 24 hours.
Understanding the Results
An abnormal result means there is too much acid in your esophagus. This could be related to:
- scars in the esophageal lining
- dysphagia (difficulty swallowing)
- Barrett’s esophagus (damaged cells in the lower esophagus)
- reflux esophagitis (inflammation of the esophagus)
If your doctor suspects esophagitis, you may need additional tests. These might include a GI endoscopy or barium swallow.
When is esophageal pH monitoring used?
Esophageal pH monitoring is used to diagnose GERD, to determine the effectiveness of medications that are given to prevent acid reflux, and to determine if episodes of acidic reflux are causing episodes of chest pain.
Monitoring esophageal pH also can be used to determine if acid is reaching the pharynx (lower throat) and is possibly responsible for such symptoms as cough, hoarseness, and sore throat.
What Are the Risks of the Test?
There are no significant risks related to this test. Rare complications include:
- inhaling vomit, if the tube causes vomiting
- an irregular heartbeat during tube insertion
What are the limitations of esophageal pH monitoring?
The demonstration of abnormal amounts of acid reflux does not mean that symptoms are being caused by the reflux.
Only treatment with medications that treat reflux coupled with a marked reduction of symptoms can be used to substantiate reflux as the cause of the symptoms.
Nevertheless, it is important to remember that treatment is associated with a placebo response. For instance, 10% to 20% of patients without acid reflux report an improvement in symptoms with anti-reflux medications.
Therefore, even a good response to treatment does not definitely prove that reflux is the cause of symptoms.
You doctor will ask you to avoid eating or drinking for 12 hours before the test. You will also need to stop smoking during this time.
Some prescription medications can affect the results of testing, Therefore, your doctor may tell you to stop taking them for up to two weeks before the test. Some drugs that affect the test include:
- adrenergic blockers (drugs that relax the muscles of the bladder and prostate)
- anticholinergics (drugs used in the treatment of spastic GI tract disorders)
- cholinergics (drugs that produce the same effects as the parasympathetic nervous system)
- corticosteroids (steroid hormones)
- H2 blockers (drugs used to block histamine effects on the stomach)
- proton pump inhibitors (drugs used to reduce gastric acid production)
Only stop taking medications if your doctor advises you to do so.
What are the side effects of esophageal pH monitoring?
There are very few side effects of esophageal pH monitoring. Although there may be mild discomfort in the back of the throat while the catheter is in place, particularly during swallows, the majority of patients have no difficulty eating, sleeping, or going about their daily activities.
Most patients, however, prefer not to go to work because they feel self-conscious about the catheter protruding from their nose. The capsule device may cause discomfort when swallowing.
The discomfort is felt in the chest and may be due to food or the wave of esophageal contraction tugging on the capsule as it passes
Are there alternatives to esophageal pH monitoring?
There are no alternatives for obtaining the information that esophageal pH monitoring provides.
Nevertheless, the presence of esophagitis visually at the time of endoscopy strongly suggests the presence of acidic reflux among patients who don’t have other likely causes of esophageal pain. This may obviate the need to do a pH monitoring study.
Outcomes and Expectations
Many people are able to manage the discomfort of heartburn by:
- making changes to their diet
- getting more exercise
- stopping smoking
- reducing caffeine and alcohol consumption
- taking over-the-counter medications
If you have GERD, these solutions may offer only temporary relief. Your doctor may recommend prescription medications to control your symptoms.
Surgery may sometimes be recommended if your GERD is caused by structural damage to your esophagus. The sphincter that closes the bottom of the esophagus may need to be repaired.
Surgery can also be used to scar the esophagus so that it no longer feels pain.