Functional gastrointestinal disorders (FGIDs) refer to a group of chronic, recurrent gastrointestinal symptoms without evidence of structural abnormalities, representing functional disorders of the gastrointestinal tract. The clinical manifestations primarily involve symptoms related to the gastrointestinal tract, including the pharynx, esophagus, stomach, biliary tract, small intestine, colon, and anus. These disorders are named based on the characteristics of their symptoms. FGIDs are associated with disturbances in gastrointestinal motility, visceral hypersensitivity, alterations in mucosal and immune function, changes in gut microbiota, and abnormalities in central nervous system processing. In recent years, greater emphasis has been placed on the role of gut-brain interaction abnormalities in their pathogenesis. While these conditions are not life-threatening, they are characterized by a significant reduction in patients' quality of life. Clinically, functional dyspepsia and irritable bowel syndrome are the most common presentations.
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