The pathogenesis of persistent non-erosive reflux disease treated with proton-pump inhibitors as measured with the Symptom Index

Background Non-erosive reflux disease (NERD) includes a heterogeneous patient group with varying clinical and pathophysiological characteristics. This study aims to elucidate the pathogenesis of persistent NERD despite of continuous proton-pump inhibitors (PPI) treatment using 24-h combined multichannel intraluminal impedance-pH monitoring (MII-pH).