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). New provocative measures, such as multiple rapid swallows and the rapid drink challenge, have been developed to overcome the limitations of standard high-resolution esophageal manometry, aiming at further clarifying esophageal dysmotility. Furthermore, the current diagnostic and therapeutic challenges in patients with esophageal involvement in Sjogren's syndrome and scleroderma, who tend to have severe forms of GERD, are entering a new investigative and clinical phase.