Only a small percentage of patients will need the tests described below. The majority of doctors will prescribe a trial of acid-suppressive therapy, and make a diagnosis based on the patient's response to this.
If a doctor decides to order a diagnostic test, it may be one of the procedures below.
The upper endoscopy (also known as esophagogastroduodenoscopy or EGD) allows the doctor to examine the inside of the patient's esophagus, stomach, and duodenum (the first part of the small intestine) with an instrument called an endoscope, a thin flexible lighted tube. The doctor will be able to see the walls and tissue of the upper digestive tract. During this procedure, a doctor may take a biopsy to see if there are any changes to the lining of the esophagus that may require further monitoring
24-hour Esophageal PH Monitor Examination
This procedure is done with a thin, plastic tube with a sensor that measures the amount of acid backing up into the esophagus. It is the most sensitive test for diagnosing GERD. The doctor inserts a tube through the nose, and the patient swallows it until it enters the esophagus. The tube is attached to a Walkman-size box that measures how often and for how long stomach acid reaches the esophagus in a 24-hour period. During this time, a patient will keep a record of symptoms. The data from the monitor is analyzed to determine the frequency of reflux, and the association of those reflux episodes to patient symptoms. The pH monitoring is particularly useful for people with ongoing symptoms who fail a trial of acid-suppressive therapy and who have a normal endoscopy exam.
Barium x-rays are diagnostic x-rays in which barium is used to diagnose abnormalities of the digestive tract. The patient drinks a liquid that contains barium, which will coat the walls of the esophagus and stomach. X-rays are then taken, which can then show if there are strictures, ulcers, hiatal hernias, erosions or other abnormalities. This test will sometimes show how efficiently the esophagus empties. Since this test is not very useful for diagnosing reflux, it may only be used in conjunction with other testing.
Manometry is a technique that records muscular pressure. A small tube is guided through the patient's nose and into the esophagus. A computer connected to the sensor on the tube will measure the muscular pressure in the esophagus and stomach. It can determine if the lower esophageal sphincter is functioning properly.
Both the barium x-rays and manometry exams have limited usefulness in diagnosing GERD, but if a patient has certain symptoms, particularly difficulty swallowing, a doctor may recommend one.