A description of the symptoms is enough for a medical diagnosis of bile reflux, states Mayo Clinic. However, distinguishing between bile reflux and acid reflux is hard, requiring additional tests, such as endoscopy, ambulatory acid tests and esophageal impedance. Bile reflux occurs when bile moves up to the stomach and the esophagus, explains Drugs.com. It may accompany acid reflux, but they are two discrete conditions.
During an endoscopy, the doctor passes an endoscope that features a camera down the throat, explains Mayo Clinic. This shows inflammation in the esophagus and stomach, and the doctor may take tissue samples to test in the lab for esophageal cancer.
Ambulatory acid tests involve an acid-measuring probe to determine when acid started backing up into the esophagus, notes Mayo Clinic. In another test, the doctor passes a catheter with a probe at the end through the nose to the esophagus. The purpose of these tests is to rule out the presence of acid reflux.
Esophageal impedance tests determine whether it is liquids or gases that reflux into the esophagus, according to Mayo Clinic. This test is effective for patients who vomit substances that are not acidic. The test involves a catheter with a probe passed into the esophagus.