Diagnosis and Testing for GERD
A thorough evaluation is necessary to prove that reflux is present. This evaluation may include a 24-hour pH test, esophageal motility test, upper endoscopy, upper GI series and a gastric emptying study. The only way to be 100% certain a person has GERD, is 24-hour pH monitoring.
The 24-hour pH Test
A small, soft tube is passed through the nose into the esophagus to measure the amount of acid (pH) present in the esophagus. It usually records the pH in the upper esophagus (channel one) and the lower esophagus (channel two). It remains in place for 24 hours. Unfortunately, shorter periods of time do not give accurate measurements of reflux.
The tube is connected to a small box that is worn on the hip. The box has a button pushed whenever symptoms occur. This allows us to correlate symptoms with the amount of acid present in the esophagus.
In addition to measuring the pH in the esophagus, the device determines when episodes of reflux occur, how long they last and how severe they are. This information is used to calculate a composite score of the variables, called the DeMeester score. A value greater than 14 is abnormal and most patients with severe reflux have values in the 200 range.
It is important for patients to stop all anti-reflux medications for one week prior to undergoing a 24-hour pH, unless otherwise directed by a physician. Once the test is complete, patients can resume medications.
Esophageal Motility Study
The esophageal motility (manometry) test, measures the motion or contraction of the esophagus and the pressures it generates during contraction. This allows us to measure the pressure and length of the lower esophageal sphincter (LES) and how well the lower esophagus contracts. It also checks for the presence of high amplitude contractions (spasms) and high LES pressures (achalasia).
The test is important because it rules out other esophageal disorders that may mimic reflux or may alter the outcome of treatment. The test is also used to make sure that the esophagus has good distal contraction, so the patient is able to tolerate a surgical procedure should it be necessary. This test also checks for achalasia. Achalasia is a disorder of the LES, in which pressures are abnormally high and the LES does not relax.
How Is an Esophageal Motility Performed?
The test is similar to a 24-hour pH test, but lasts only about one to two hours. Once again, a small tube is passed via the nose into the esophagus. Pressures in the esophagus are measured from 5 sites (channels). Swallowing dry and wet determines not only the pressures present, but also the coordination of the contractions in the esophagus. As the upper esophagus contracts, the lower esophagus should relax.
Frequently Asked Questions
Common questions regarding the diagnosis of GERD include:
No, but it means a different type of operation is necessary. A partial, rather than a complete wrap, will be performed if needed.
No, but symptoms may not completely go away after surgery. Fortunately, most esophageal spasm that occurs concomitantly with reflux does go away if the reflux is eliminated. However, primary esophageal spasm in the absence of reflux will not go away with anti-reflux therapy. This is seen in about 50% of cases of esophageal spasm.
No, but the operation for achalasia is radically different from the standard anti-reflux operation. The surgical treatment of achalasia involves cutting the lower esophageal sphincter to eliminate the high pressure area, followed by an anti-reflux procedure.
An EGD is an esophagogastroduodenoscopy, also known as an upper endoscopy. A tube about ½ inches in diameter is placed through the mouth into the esophagus, stomach and then duodenum. The tube, which is actually a scope, is attached to a video monitor, allowing the doctor performing the procedure to look at those three organs for abnormalities such as reddening, ulcers and tumors. It is a very common procedure that lasts only a few minutes and is usually performed with sedation.
A gastric emptying study is one that measures the amount of time it takes for a meal to leave your stomach. Normally this takes less than 90 minutes. People who have diabetes or a lot of scarring from peptic ulcer disease may have significantly prolonged emptying of their stomach.
The gastric emptying test is a painless test in which one is asked to ingest eggs or hamburger that has been labeled with a tiny amount of radiation. The radiation present is less than that in a watch or that one is exposed to during an airplane trip. A special (gamma) camera counts the radioactivity in the stomach at different time intervals, thereby allowing the calculation of how long it takes the stomach to empty.
An upper GI series is a series of x-rays taken as a chalky, pink liquid (barium) is swallowed. This allows the radiologist to observe how things go down the esophagus and to see if any abnormalities exist. It also allows the radiologist to determine if a hiatal hernia is present.
Most patients undergo all of these tests. It is important to be 100% sure that the diagnosis is correct, that no other esophageal disorders exist and that the esophagus contracts well prior to any surgery. However, decisions can be made in some case by using only a few of these tests.