Retrograde flow of gastric contents to the upper aerodigestive tract causes a variety of symptoms such as cough, asthma and hoarseness. These respiratory manifestations of the reflux disease are commonly called laryngopharyngeal reflux (LPR) or extraesophegeal reflux disease (EERD). Distal esophageal pH monitoring has been used as an objective test to establish reflux as the cause of the atypical reflux symptoms but, its role in causally associating patients' symptoms to GERD is controversial.