Heartburn is a burning feeling in the chest caused by stomach acid travelling up towards the throat (acid reflux). The esophagus of most patients with symptoms of reflux looks normal. Therefore, in most patients, endoscopy will not help in the diagnosis of GERD. However, sometimes the lining of the esophagus appears inflamed (esophagitis). Moreover, if erosions (superficial breaks in the esophageal lining) or ulcers (deeper breaks in the lining) are seen, a diagnosis of GERD can be made confidently. Endoscopy will also identify several of the complications of GERD, specifically, ulcers, strictures, and Barrett’s esophagus. Biopsies also may be obtained.
The acid perfusion test, however, is used only rarely. A better test for correlating pain and acid reflux is a 24-hour esophageal pH or pH capsule study during which patients note when they are having pain. It then can be determined from the pH recording if there was an episode of acid reflux at the time of the pain. This is the preferable way of deciding if acid reflux is causing a patient’s pain. It does not work well, however, for patients who have infrequent pain, for example every two to three days, which may be missed by a one or two day pH study. In these cases, an acid perfusion test may be reasonable.
Esophageal motility testing determines how well the muscles of the esophagus are working. For motility testing, a thin tube (catheter) is passed through a nostril, down the back of the throat, and into the esophagus. On the part of the catheter that is inside the esophagus are sensors that sense pressure. A pressure is generated within the esophagus that is detected by the sensors on the catheter when the muscle of the esophagus contracts. The end of the catheter that protrudes from the nostril is attached to a recorder that records the pressure. During the test, the pressure at rest and the relaxation of the lower esophageal sphincter are evaluated. The patient then swallows sips of water to evaluate the contractions of the esophagus.
A new technology allows the accurate determination of non-acid reflux. This technology uses the measurement of impedance changes within the esophagus to identify reflux of liquid, be it acid or non-acid. By combining measurement of impedance and pH it is possible to identify reflux a knockout post and to tell if the reflux is acid or non-acid. It is too early to know how important non-acid reflux is in causing esophageal damage, symptoms, or complications, but there is little doubt that this new technology will be able to resolve the issues surrounding non-acid reflux.
Information from the emptying study can be useful for managing patients with GERD. For example, if a patient with GERD continues to have symptoms despite treatment with the usual medications, doctors might prescribe other medications that speed-up emptying of the stomach. Alternatively, in conjunction with GERD surgery , they might do a surgical procedure that promotes a more rapid emptying of the stomach. Nevertheless, it is still debated whether a finding of reduced gastric emptying should prompt changes in the surgical treatment of GERD.