Reflux monitoring has advanced from inpatient continuous pH recordings on scrolling graph paper introduced 50 years ago to modern catheter-based 24-hour and wireless multiple-day ambulatory recordings, and the capability of detecting reflux episodes irrespective of pH using impedance technology. Testing is performed off antisecretory therapy when there is no prior documentation of reflux disease, and pH-impedance monitoring can be performed on therapy in symptomatic patients with proven reflux. Prolonged wireless pH monitoring evaluates day-to-day variation in reflux exposure. New impedance-based metrics evaluating baseline impedance and post-reflux swallow induced peristaltic wave have potential to augment the diagnostic value of reflux monitoring.
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