ESOPHAGUS: Edited by Stuart J. SpechlerRecent insights on functional heartburn and reflux hypersensitivitySavarino, Edoardoa; Marabotto, Elisab; Savarino, Vincenzob Author Information aGastroenterology Unit, Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua bGastroenterology Unit, Department of Internal Medicine and Medical Specialties, University of Genoa, Genoa, Italy Correspondence to Vincenzo Savarino, MD, PhD, Department of Internal Medicine, University of Genoa, Viale Benedetto XV, Genova, Italy. Tel: 0039-010-3538956. e-mail: [email protected] Current Opinion in Gastroenterology 38(4):p 417-422, July 2022. | DOI: 10.1097/MOG.0000000000000846 Buy Metrics Abstract Purpose of review Rome IV experts have proposed that gastroesophageal reflux disease (GERD) should be diagnosed only in patients with abnormal esophageal acid exposure, and that reflux hypersensitivity (RH) and functional heartburn (FH) both should be considered functional conditions separate from GERD. Although past and recent evidence support that FH can be completely distinguished from GERD, the concept that RH is not GERD is highly questionable. This review attempts to provide current data on these issues. Recent findings Many recent investigations have provided new data on the different pathophysiological features characterizing RH and FH. Major differences have emerged from analyses of impedance-pH monitoring studies using the novel impedance metrics of baseline impedance (an index of mucosal integrity) and the rate of postreflux swallow-induced peristaltic waves (a reflection of the integrity of esophageal chemical clearance). Summary The better ability to interpret impedance-pH tracings together with earlier data on the different prevalence of microscopic esophagitis in RH and FH patients, and recent studies documenting poor therapeutic efficacy of pain modulators and good results of antireflux surgery for RH support recategorization of RH within the GERD world. Further research is needed to correctly phenotype patients who have heartburn without mucosal breaks, and to guide their effective management. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.