Services & Procedures

24-Hour pH Monitoring in Philadelphia, PA

The lower esophageal sphincter is a specialized muscle at the lower end of the esophagus which remains tightly closed most of the time. This is supposed to open only to allow food and liquids to enter the stomach. Occasionally, the lower esophageal sphincter opens inappropriately, allowing stomach acid and bile to wash up into the esophagus. This is called acid reflux and can cause discomfort and heartburn. Almost everyone has experienced heartburn occasionally but when it happens on a regular basis, it can lead to damage and scarring in the esophagus.

pH is a measure of the acidity. Most people are familiar with pH tests done on soil or a swimming pool. An esophageal pH test measures how often stomach acid flows into the lower esophagus and the degree of acidity during a 24-hour period.

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The equipment for esophageal pH consists of a small thin probe at the end of tubing. This probe measures acidity. The tubing is gently inserted through the nose, down to the end of the esophagus. It is attached to a small portable recorder that is carried on the patient’s waist. Over a 24-hour period, the acidity in the lower esophagus is recorded. When the patient experiences reflux or other symptoms, the patient presses a button on the recorder. This marks a time so the physician can see how it relates to the acid level measured by the probe. The recorder is then analyzed and a report sent to the physician.

Reasons for the Exam

There are a number of symptoms that originate in the esophagus including heartburn, difficulty swallowing of food or liquid, and chest pain. A measure of the esophageal pH is of great importance in evaluating symptoms and allows the physician to diagnose and treat problems of acid reflux. This exam is often done before and after medical and surgical treatment of acid reflux into the esophagus.


The preparation for esophageal pH measurement is very simple. The patient should have no liquids or food for at least eight hours before the exam. Usually, the physician will want to study the esophagus in its natural state. In other words there should not be any medication in the body that can affect the function of the esophagus.

Patients should review all medications they are taking with their physicians, so they can be advised which should and should not be taken before the test.


It takes about 10 to 15 minutes to insert and place the pH probe. While the patient is seated in a chair or lying on his/her side, a soft thin tube is passed through the nose. Upon swallowing, the tip of the tube enters the esophagus and the nurse or technician quickly passes it down to the desired level. There may be some slight gagging at this point, but it is usually controlled by following instructions. The tubing is then attached to the waist recorder and the patient is sent on to his/her regular daily activities.


Generally, an esophageal pH test will show a small amount of acid seeping into the esophagus at various times during the day and night. This is normal for almost everyone and the patient may not even be aware of these symptoms. However, if the usual protective mechanisms of the esophagus do not function properly, the test will show a greater degree and duration of stomach acid in the esophagus.

Benefits and Alternatives

The primary benefit of the exam is that the physician has clear documentation of the degree and duration of acidity in the esophagus. With this information, a specific treatment program can be outlined or reassurance provided if the exam is normal.

Other examinations may be used to study the esophagus such as upper GI series and endoscopy but nothing takes the place of esophageal pH monitoring. This is often done in association with esophageal manometry.

Side Effects and Complications

Generally, there are no serious problems associated with esophageal pH testing. Once the tube is in place, it is usually easily tolerated.

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If you suffer from esophageal pain due to stomach acidity, contact an acid reflux doctor near Philadelphia today by calling our office at (610) 644-6755.