Functional Dyspepsia Demystifying for Clinicians

Rome IV diagnostic criteria for functional dyspepsia necessitate the presence of one or more bothersome symptoms such as postprandial fullness, early satiation, epigastric pain or epigastric burning. Additionally, there should be no evidence of a disease, as determined by negative fi ndings in upper endoscopy, likely to explain the symptoms.

Immune function, infl ammation and epithelial permeability play a role in functional dyspepsia, with low-grade mucosal infl ammation, increased eosinophils and mast cells in the stomach and duodenum, and elevated duodenal eosinophil levels in both epigastric pain syndrome and postprandial distress syndrome cases. A higher incidence of atopy and food allergy is also noted.

Psychology is intertwined with functional dyspepsia, as anxiety and depression are commonly associated. Stress, whether from pain or psychological comorbidities, can upregulate the hypothalamic-pituitary-adrenal axis, increasing corticotropin-releasing hormone levels and activating local infl ammatory processes, potentially affecting gut function, including epithelial permeability, immune function and the microbiome.

Overlap is a well-established phenomenon in functional GI disorders. Patients with overlap syndromes tend to experience more severe symptoms, with motor dysfunction in one GI tract segment impacting motility in another. Sensorimotor disorders are often generalized, and common mechanisms partially explain the observed overlap.