BRAVO pH study measures and records the pH (acid) in your esophagus to determine if your have GERD or gastroesophageal reflux disease. This is a condition in which stomach acid refluxes (moves) back into the esophagus (the “food” pipe). The lower esophageal sphincter is located where the esophagus meets the stomach. The sphincter opens to allow food and liquid to pass into the stomach and closes. When the sphincter does not close tightly, food particles, stomach acid and other digestive juices can splash back up the esophagus (reflux). This test will measure how often stomach contents reflux into the lower esophagus and how much acid the reflux retains. A small capsule, about the size of a gel cap, is temporarily attached to the wall of the esophagus during an upper endoscopy while you are sedated. The levels are transmitted to a receiver (about the size of a pager) worn on your belt or waistband. After 48 hours, the patient will return the receiver and the capsule will pass naturally in a bowel movement. This can be flushed away. You may not notice that it has passed. This procedure takes approximately 20 minutes with an additional 30-60 minutes recovery time. You will need a driver because of the sedation.