In Asia, up to 70% of patients with typical gastroesophageal reflux symptoms could have non-erosive reflux disease (NERD), in which case, no detectable mucosal break may be observed on conventional white-light endoscopy. However, minimal change lesions are often visible upon high-resolution endoscopy and on microscopic examination of biopsied specimens. The most commonly seen microscopic features are dilated intercellular space, infiltration of inflammatory cells into squamous epithelia, hyperplasia of the epithelial basal cell and elongation of the papillae. So far, the most consistent histologic change found in NERD has been the dilated intercellular space in esophageal epithelium. But until now, determinations of intercellular space dilatations could only be done ex-vivo on biopsy specimens using transmission electron microscopy or light microscopy. With the advent of high-resolution confocal laser endomicroscopy, in-vivo determination of intercellular space dilatations and other diagnostic microscopic features could be a reality. This study is aimed at exploring such a clinical possibility and feasibility, with the intention of comparing the microscopic findings based on confocal endomicroscopy with that of symptoms, and esophageal pH.