Reflux or backflow of the acidic contents of the stomach into the esophagus can occur due to dysfunctional lower esophageal sphincter (LES) muscles. This can lead to a condition called gastroesophageal reflux disease (GERD) which gradually damages the esophagus and can lead to esophageal cancer. To determine the extent of gastroesophageal reflux, a 24-hour pH monitoring test may be performed.
Prior to the test, you are asked to gradually withdraw from all acid-regulating medication and fast for a period of 4-6 hours.
During this test your doctor places a thin tube through your nose and down your esophagus. The tip of the tube has a sensor that can detect acidity levels, and is positioned around 2 inches above the LES. The other end of the tube is taped to the side of your face and connected to a portable recording device fixed to your belt or shoulder. The device stays in for a period of 24 hours and has buttons to indicate activities such as eating and sleeping. The test results measure the level of acidity and amount of stomach content refluxing into the esophagus and determines the presence and severity of gastroesophageal reflux disease.