Since the tube is placed for a short duration, it is usually placed in the mouth since access is easier than through the nose. Some drugs and medications may alter the test results, and therefore your health care provider may ask you to withhold those substances for 24-hours before the test. You may experience a brief gagging sensation as the catheter is passed through your throat. Esophageal pH monitoring is used to assess how much stomach acid is entering the esophagus and how well it is cleared. In infants, this test is usually used to evaluate the absence or presence of GERD and associated excessive crying or other problems.
Normal values vary from person to person, and with different equipment and technique.
Information not available.