Pathophysiology of functional constipation

Chronic constipation is a complex, heterogeneous gastrointestinal disorder characterized by a multifactorial pathophysiology encompassing neuromuscular, sensory, microbial, and central mechanisms. Rather than a discrete disease entity, chronic constipation comprises a continuum of overlapping pathophysiological phenotypes, which accounts for its marked clinical heterogeneity and variable therapeutic responsiveness. From an integrative standpoint, comprehensive pathophysiological characterization of chronic constipation should incorporate colonic transit assessment, high-resolution colonic manometry, anorectal manometry, rectal sensory testing, and meticulous clinical phenotyping. This multimodal approach enables delineation of the predominant underlying mechanism in individual patients and supports the implementation of personalized, mechanism-targeted therapeutic strategies, in accordance with contemporary pathophysiological frameworks of chronic constipation.