Other Tests Used to Confirm GERD
Another common test is called an endoscopy. Endoscopy is a procedure where a small flexible tube is inserted through your mouth and into your esophagus. This tube also has a camera attached to it so that your doctor can look for problems in your esophagus and stomach. A biopsy, or small piece of tissue, may be removed for further study if anything is found that doesn't look normal. A tissue sample may also help your doctor determine how severe your GERD is.
A test called esophageal manometry can be done to see if the contractions of your esophagus are especially weak. This is done by inserting a small flexible tube into your throat to monitor peristalsis and to check the strength of the lower esophageal sphincter. If the sphincter and/or peristalsis are found to be weak, it may explain why you are having symptoms.
Esophageal pH Test
An esophageal pH test may be done in order to confirm your GERD diagnosis and measure the amount of acid reflux into your esophagus at different times during the day. This can be used, for example, to see if acid reflux only happens when you are lying down or at night after you go to bed. This test is also useful in people who have GERD symptoms but no esophageal damage. A pH test is helpful in detecting whether respiratory symptoms, including wheezing and coughing, are triggered by reflux.