Esophageal pH











The preparation for esophageal pH measurement is very simple. The patient should take no food or liquid for about 8 hours before the exam. In most cases, the physician will want to study the esophagus in its natural state. In other words, there should not be any medicine in the body that can affect the function of the esophagus.

An important part of esophageal PH preparation is that patients should review all medications they are taking with their physicians, so they can be advised which they should and should not be taking before the test. Generally, the following list of drugs may affect how much acid flows into the esophagus. They usually need to be discontinued at least 48 hours before the test. However, do not stop taking any medication without consulting the physician.

Caffeine (coffee, tea, cola, chocolate)


Reglan (generic: metoclopramide)

Urecholine (generic: bethanechol)

Erythromycin (E-Mycin, and others)

Nitroglycerin (Isordil, and others)

Calcium channel blockers, (Procardia, Adalat, Calan, Cardizem, and others)

Beta blockers (Corgard, Inderal, Lopressor, and others)




Tagamet (generic: cimetidine)

Zantac (generic: ranitidine)






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


Normally there are several mechanisms that keep acid out of the esophagus. The first is swallowed saliva which helps neutralize stomach acid. Second are the sweeping muscle contractions that act to cleanse the lower esophagus of acid reflux. Third is the protective contraction of the LES. Generally, the 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 symptoms. However, if the above protective actions of the esophagus do not function properly, the test will show a greater degree and duration of stomach acid in the esophagus.


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 can be provided if the exam is normal.

While there are other examinations used to study the esophagus, such as upper GI series and endoscopy, nothing really takes the place of esophageal pH measurement. Esophageal pH is often done in association with a pressure recording of the esophagus, known as Esophageal Manometry.


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


Esophageal pH is a valuable method of determining the severity of acid reflux into the esophagus. With this information, the physician can usually develop effective treatment plan for most patients who have acid disorders in the lower esophagus and the esophageal PH test results are fruitful and long-lasting.

For more information about esophageal PH test, visit our clinic or contact us in Riverdale NJ.

Book an appointment with Dr. Dasani >>>

Our Locations

Choose your preferred location