Heartburn is a burning feeling in the chest caused by stomach acid travelling up towards the throat (acid reflux). The action of the lower esophageal sphincter (LES) is perhaps the most important factor (mechanism) for preventing reflux. The esophagus is a muscular tube that extends from the lower throat to the stomach. The LES is a specialized ring of muscle that surrounds the lower-most end of the esophagus where it joins the stomach. The muscle that makes up the LES is active most of the time, that is, at rest. This means that it is contracting and closing off the passage from the esophagus into the stomach. This closing of the passage prevents reflux. When food or saliva is swallowed, the LES relaxes for a few seconds to allow the food or saliva to pass from the esophagus into the stomach, and then it closes again.
The advantage of the capsule over standard pH testing is that there is no discomfort from a catheter that passes through the throat and nose. Moreover, with the capsule, patients look normal (they don’t have a catheter protruding from their noses) and are more likely to go about their daily activities, for example, go to work, without feeling self-conscious. Because the capsule records for a longer period than the catheter (48 versus 24 hours), more data on acid reflux and symptoms are obtained. Nevertheless, it is not clear whether obtaining additional information is important.
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.
Some doctors believe a hiatal hernia may weaken the LES and increase the risk for gastroesophageal reflux. Hiatal hernia occurs when the upper part of the stomach moves up into the chest through a small opening in the diaphragm (diaphragmatic hiatus). The diaphragm is the muscle separating the abdomen image source from the chest. Recent studies show that the opening in the diaphragm helps support the lower end of the esophagus. Many people with a hiatal hernia will not have problems with heartburn or reflux. But having a hiatal hernia may allow stomach contents to reflux more easily into the esophagus.
pH testing also can be used to help evaluate whether reflux is the cause of symptoms (usually heartburn). To make this evaluation, while the 24-hour ph testing is being done, patients record each time they have symptoms. Then, when the test is being analyzed, it can be determined whether or not acid reflux occurred at the time of the symptoms. If reflux did occur at the same time as the symptoms, then reflux is likely to be the cause of the symptoms. If there was no reflux at the time of symptoms, then reflux is unlikely to be the cause of the symptoms.