New developments in esophageal function testing and esophageal manifestations of connective tissue disorders.

This work summarizes new and emerging metrics and tools in esophageal function testing and their potential clinical impact. Because the diagnostic sensitivity and reliability of conventional impedance-pH variables are suboptimal, several novel impedance parameters, such as the postreflux swallow-induced peristaltic wave index and the mean nocturnal baseline impedance, as well as mucosal impedance, are entering a validation stage prior to general clinical use. The accurate diagnosis of behavioral disorders in patients with rumination syndrome and supragastric belching using ambulatory multiple intraluminal impedance-pH can lead directly to behavioral interventions in patients with refractory gastroesophageal reflux disease (GERD).