Pathophysiological mechanisms of functional dyspepsia: a narrative review.

Background: Functional dyspepsia (FD) is a common gastrointestinal disorder with a global prevalence of about 40%. Its pathogenesis is multifactorial and not fully understood, which complicates diagnosis and treatment. Advances in research have improved understanding of the mechanisms underlying FD, offering opportunities to refine diagnosis and therapy. Summary: FD presents with upper abdominal discomfort, bloating, belching, and nausea, in the absence of structural disease. Its heterogeneous pathogenesis involves impaired gastric accommodation, delayed gastric emptying, mucosal immune activation, microbiota imbalance, altered neuroendocrine and sensory processing, and psychosocial influences. While treatment options have expanded, challenges remain due to overlapping symptoms and variability among patients. Key messages: FD is associated with abnormalities in gastrointestinal motility, immune responses, brain-gut interactions, and psychosocial factors. Recognizing its heterogeneity is crucial for developing individualized management strategies. Better characterization of patient subtypes may improve diagnostic accuracy, guide therapy, and ultimately enhance clinical outcomes.