The test is used to check whether one suffers from laryngopharyngeal reflux or to evaluate the drug effectiveness against laryngopharyngeal reflux.
Laryngopharyngeal reflux refers to the flow of stomach contents (gastric contents) beyond the muscle ring of the top of the digestive tract (upper oesophageal sphincter) and to the back of the throat and the nasal airway (larynopharynx), causing mucosa inflammation and thus various types of respiratory symptoms. Some people may have sound hoarseness, chronic cough and throat clearing etc. The reflux occurs more often when awake than sleeping.
As for infant and children, the symptoms include: