Gastroesophageal reflux (GOR) is defined as “the passage of gastric contents into the esophagus with or without regurgitation and vomiting” and gastroesophageal reflux disease (GORD) is defined “when GOR leads to troublesome symptoms affecting the daily functioning and/or complications.” This definition was first developed in 2006 by the Montreal consensus group (1) and later on adopted by pediatric gastroenterology societies such as ESPGHAN and NASPGHAN in 2009 (2). The definition of gastroesophageal reflux reveals little about its pathophysiology and is focused on symptomatology. In this way, it acts as an umbrella term for the multifactorial causes of the disease and the various phenotypes encountered; from functional heartburn to hypersensitive esophagus and nonerosive reflux disease, to erosive esophagitis and Barrett’s esophagus. This article is devoted to the pathophysiology of pediatric GORD in comparison to adult GORD and is divided in 2 parts. In the first part, we will systematically describe the different mechanisms for the generation and clearance of reflux events, while on the second part we will discuss the mechanisms involved in symptoms generation. Finally, we will discuss the similarities and differences between pediatric and adult GORD.

胃食管反流（GOR）被定义为“胃内容物进入食管，伴或不伴反流和呕吐”，胃食管反流病（GORD）被定义为“当 GOR 导致影响日常功能和/或并发症的麻烦症状时”。该定义最初由蒙特利尔共识小组于 2006 年制定 (1)，随后于 2009 年被 ESPGHAN 和 NASPGHAN 等儿科胃肠病学会采用 (2)。胃食管反流的定义很少揭示其病理生理学，而是集中于症状学。通过这种方式，它成为疾病的多因素原因和遇到的各种表型的总称；从功能性胃灼热到过敏性食管和非糜烂性反流病，再到糜烂性食管炎和巴雷特食管。本文致力于探讨儿童 GORD 与成人 GORD 的病理生理学比较，分为两部分。在第一部分中，我们将系统地描述反流事件产生和清除的不同机制，而在第二部分中，我们将讨论症状产生所涉及的机制。最后，我们将讨论儿童和成人 GORD 的异同。