Esophageal pH monitoring, indications, and methods.

Symptomatic gastroesophageal reflux disease (GERD) is a common problem that affects a substantial proportion of the American population. It is estimated that the symptoms of GERD may afflict 40% to 45% of Americans each month. The diagnosis of GERD can be difficult, as its symptoms vary from typical symptoms like heartburn to atypical symptoms such as hoarseness, coughing, and chest pain. Most patients present with typical symptoms and are diagnosed with GERD if they respond to empiric trials of acid suppression. Many tests are available to help with diagnosing GERD in patients who either present with atypical symptoms or who do not respond to acid suppression; however, each test has its own shortcomings. The only test that directly measures whether acid is refluxing into the esophagus is the pH probe, but this test is uncomfortable for the patient, can be difficult to interpret, and may not be necessary in all cases. This article reviews the indications for pH monitoring, its technique, its advantages and limitations, and its role the diagnosis of GERD.