The Real-world Gastritis Initiative (RE.GA.IN.) aims to update the state of the art on gastric inflammatory diseases and provide evidence-based information for clinical practice. The initiative involved experts from five continents who engaged in eight months of virtual discussions and a two-day in-person meeting in Venice. The consensus process focused on topics such as the epidemiology of gastritis, the role of Helicobacter pylori, gastric autoimmunity, the clinicopathological relevance of the gastric microbiota, and new diagnostic techniques. The final report includes eight sections addressing clinicopathologically homogeneous topics, with each section containing a preamble and explanatory text. The consensus process emphasized the importance of distinguishing between different gastritis subtypes and defining the normal gastric mucosa to avoid misdiagnosis. The report also highlights the importance of histological reporting in staging gastritis and the clinical priority of using validated staging systems. The initiative aims to improve the clinical management of patients with gastritis by promoting evidence-based practices and guidelines. The consensus process was supported by the International Menarini Foundation and involved a rigorous scientific approach to ensure the reliability of the findings. The final document was approved by all participating experts and includes recommendations for the diagnosis and management of gastritis, including the use of non-invasive tests and the importance of histological evaluation. The report also addresses the role of artificial intelligence in clinical gastritis management and the need for further research to understand the pathogenesis of gastritis and its preneoplastic lesions.The Real-world Gastritis Initiative (RE.GA.IN.) aims to update the state of the art on gastric inflammatory diseases and provide evidence-based information for clinical practice. The initiative involved experts from five continents who engaged in eight months of virtual discussions and a two-day in-person meeting in Venice. The consensus process focused on topics such as the epidemiology of gastritis, the role of Helicobacter pylori, gastric autoimmunity, the clinicopathological relevance of the gastric microbiota, and new diagnostic techniques. The final report includes eight sections addressing clinicopathologically homogeneous topics, with each section containing a preamble and explanatory text. The consensus process emphasized the importance of distinguishing between different gastritis subtypes and defining the normal gastric mucosa to avoid misdiagnosis. The report also highlights the importance of histological reporting in staging gastritis and the clinical priority of using validated staging systems. The initiative aims to improve the clinical management of patients with gastritis by promoting evidence-based practices and guidelines. The consensus process was supported by the International Menarini Foundation and involved a rigorous scientific approach to ensure the reliability of the findings. The final document was approved by all participating experts and includes recommendations for the diagnosis and management of gastritis, including the use of non-invasive tests and the importance of histological evaluation. The report also addresses the role of artificial intelligence in clinical gastritis management and the need for further research to understand the pathogenesis of gastritis and its preneoplastic lesions.