24-hour esophageal pH-test

What is 24-hour esophageal pH-test?

24-hour esophageal pH-test is a method of examining the state of the upper parts of the gastrointestinal tract. It is based on extensive measurement of the pH level in the esophagus, stomach, and duodenum using a special device – a stomach acid monitor.

Normal pH-level is achieved through the sufficient production of hydrochloric acid, and a timely and well-coordinated work of the muscles of digestive organs. If those functions are impaired, acid-related diseases occur, such as ulcerative disease, gastritis, esophagitis.

24-hour esophageal pH-test helps to:

  • assess the process of stomach acid formation throughout 24 hours while the body is functioning normally, as well as to determine the effect that various factors, such as food, medications, smoking, the position of the body, have on the stomach acidity.
  • to identify duodenal reflux and gastroesophageal reflux (the return of the duodenum or stomach content back into stomach or esophagus), to assess its frequency, duration, and effect over the mucous membrane of the stomach or esophagus. To determine the factors that provoke reflux.
  • to assess the effectiveness of antisecretory or other therapy.
  • to obtain data on the condition of the esophagus and stomach, including assessment after or before surgery.
  • in order to change the diet based on individual acid rhythms of the stomach.

The device used for the test is portable, and the test itself is relatively easy to perform, which allows the patient to keep his/her normal level of activity during the examination.

24-hour esophageal pH-test at Kivach Clinic


  • Gastroesophageal reflux disease (GERD) or the return of the stomach content back up into the esophagus.
  • Diagnosis of endoscopy-negative reflux disease (the absence of visible changes in the mucous membrane of the esophagus during endoscopy).
  • Suspicion of non-esophageal GERD manifestations: chest pain, choking, hoarse voice.
  • Heartburn, belching, bitter taste in the mouth.
  • Ulcer disease.
  • Chronic gastritis.
  • Zollinger-Ellison syndrome.
  • To monitor the effectiveness of the treatment.
  • To find an individual treatment regimen.

What to expect during the test?

A stomach acid monitor called “Gastroscan 24” is used at Kivach Clinic. It consists of a pH-probe – a thin, flexible tube, and a portable monitor.

The patient is seated during the procedure. The nose and throat are sprayed with an anesthetic. After that, the doctor inserts a pH-probe. This way, there are less uncomfortable sensations, such as retching, and it does not interfere with breathing or eating. After the probe passes the nasopharynx, the patient is asked to perform a couple of swallowing movements, so that the probe moves down the esophagus. The probe is positioned in the stomach or duodenum, depending on the test objective.

An electrometric method is used to determine pH-level. The data obtained from the probe is converted into an electrical signal and sent to the monitor, which hangs over the shoulder on a strap. An electrode is placed onto a patient's skin – to compare the signal with permanent pH.

After the preparation is over, the test itself – the recording of acidity levels during 24 hours, begins.

The patient can eat 40 minutes after the probe is placed into the stomach.

During the examination it is recommended to avoid carbonated drinks, alcohol, tomatoes, marinades, coffee, sour products.

A patient has to keep a diary, which includes the information about the following: changes in how the patient feels, meal times, physical activity, sleep time and changes in the position of the body, the time of drug intake.

After the examination, the probe is easily removed. The doctor analyzes the data and issues a medical conclusion after 1-2 days.


Absolute contraindications are:

  • Gastrointestinal bleeding (including the bleeding from varicose veins in the esophagus, Mallory-Weiss syndrome). The examination is performed at least ten days after the bleeding is over.
  • Aortic aneurysm.
  • The results of esophageal burns, narrowing of the esophageal lumen and diverticulum.
  • Hypertensive crisis, uncontrolled arterial hypertension.
  • Severe ischemic heart disease.
  • Inability to breathe through the nose.
  • Severe blood clotting disorders.

Relative contraindications are:

  • surgical intervention of the upper gastrointestinal tract less than six months ago;
  • tumors, ulcers, deep erosions of the esophagus;
  • varicose veins in the esophagus.


  1. Is the test safe?
  2. Yes, the test is safe.

  3. Is the test painful?
  4. The test is painless. There might be retching when the probe is being put into place. During the test, the patient might feel some discomfort in the nasopharynx, as well as the presence of a foreign object in the esophagus. This sensation does not affect daily routine and is over after the probe is taken out.

  5. How to prepare for the procedure?
  6. In order to exclude the presence of possible contraindications, the patient has to have a gastroscopic examination.

    24-hour esophageal pH-test is done on an empty stomach – the last meal should be 12 hours before the test, and it is forbidden to smoke and drink 3-4 hours before the test.

    In some cases, the doctor might cancel the intake of antisecretory drugs during the test – proton-pump inhibitors 72 hours before the test, H2 receptor blockers 24 hours before the test, antacids and anticholinergics 12 hours before the test.

    On the day of the test after the probe is installed, the patient sticks to his/her normal lifestyle and diet. On this day, gall bladder cleansing, hydrotherapeutic procedures, physiotherapeutic procedures, magnetic therapy, wrappings, saunas and cryosauna are cancelled.

  7. Are complications possible?
  8. In order to avoid complications, a patient must inform the doctor about his/her state of health and allergic reactions. It is necessary to perform an EGD to exclude the presence of contraindications. In some cases, there might be nasal discharge after the probe is put into place, which is not the reason to stop the testing.

  9. Why does the test take 24 hours?
  10. Acid production in the stomach and the work of the digestive system have a cyclical nature. The minimal cycle of the work of the gastrointestinal tract is 24 hours. That is why a 24-hour test helps to obtain maximum data about the functioning of the upper digestive tract.

    The test at night when the patient is in a horizontal position helps to get a full picture of the state of the esophagus.

    Apart from that, measuring pH over a long period helps to find "weak" spots in the treatment using drugs that lower the acidity, and adjust the dosage and drug intake time.

  11. What ensures that the procedure is successful?
    • Qualified medical specialists with extensive practical experience.
    • Advanced equipment.
    • Compliance with the standards of medical care.