Functional Dyspepsia: An Updated Review of Pathophysiology, Epidemiology, Clinical Manifestations, and International Management Guidelines.

Background: Functional dyspepsia (FD) is a prevalent yet challenging gastrointestinal disorder described as a group of upper gastrointestinal symptoms such as epigastric pain or burning, bloating, belching among many others, in the absence of an identifiable organic etiology. Its diagnosis is established according to the Rome IV criteria, which define the disorder by bothersome postprandial fullness, early satiety, epigastric pain and/or epigastric burning present for the last 3 months, with symptom onset at least 6 months before diagnosis. Despite its benign nature, functional dyspepsia can considerably affect patients' quality of life and constitutes a significant burden on healthcare systems worldwide, as it is estimated to affect over 20% of the population. FD can be subdivided into the three following subtypes - postprandial distress syndrome (PDS), epigastric pain syndrome (EPS) and a constellation of both - based on symptoms' pattern. Objectives: This article provides a comprehensive overview of the epidemiology, pathophysiology, subtypes, clinical presentation as well as management strategies of functional dyspepsia. Understanding these aspects is crucial for improving diagnosis and applying effective treatment strategies for patients with functional dyspepsia. Design: Narrative literature-based review. Methods: We conducted a search of PubMed/MEDLINE, Embase, and Google Scholar for publications from January 2010 to March 2025, including clinical studies, reviews, and international guidelines related to functional dyspepsia. Results: The pathophysiology of functional dyspepsia remains poorly understood, largely due to its multifactorial nature. Several factors at both the macroscopic and microscopic level have been implicated in the pathogenesis of this disorder such as altered gastrointestinal motility, impaired barrier function, altered gut-brain axis, inflammation as well as psychological factors. Several clinical guidelines, both European and American, have been developed to guide the diagnosis of functional dyspepsia and its management with the primary goal of symptom control. Conclusion: Functional dyspepsia remains a complex disorder due its diverse clinical features and multifactorial etiology. A patient-centered approach and management based on recent guidlines are essential for effective management of this condition.