Clinical methods to evaluate the properties of oesophageal physiology have expanded over the past 20 years, each with distinct advantages and implications. Ambulatory reflux monitoring, the mainstay method to evaluate for acidic gastro-oesophageal reflux, measures the amount of time the pH is below 4.0 in the oesophagus. 1 In clinical practice a common question regards which ambulatory reflux monitoring tool to use: wireless pH telemetry or multi-channel intraluminal impedance-pH (MII-pH) transnasal catheter?Recent high-level data highlight the value of prolonged wire-Pharmaceuticals; Advisory Board with Stock Options: RJS