[Recent Advances in Esophageal Function Testing for Functional Esophageal Disorders]

Functional esophageal disorders are heterogeneous conditions characterized by esophageal symptoms without definite structural obstruction or major mucosal disease. Recent advances in high-resolution manometry, the Chicago Classification version 4.0, provocative maneuvers, timed barium esophagography, and functional lumen imaging probe have substantially changed the diagnostic approach to these disorders. Although high-resolution manometry remains the cornerstone of esophageal motility assessments, normal or borderline manometric findings do not always indicate a normal esophageal physiology. In particular, the integrated relaxation pressure has important limitations because it reflects pressure-based relaxation rather than actual esophagogastric junction opening. A functional lumen imaging probe provides complementary information by assessing esophagogastric junction distensibility and distension-induced contractile responses. This approach may reveal subtle obstructive physiology, impaired distensibility, or abnormal wall biomechanics that are not evident on conventional manometry. Emerging concepts, such as manometry-functional lumen imaging probe discordance, esophageal wall thickening-associated dysphagia, and distension-mediated obstruction, suggest that some patients previously diagnosed with functional dysphagia may have identifiable and potentially treatable physiologic abnormalities. Therefore, the evaluation of functional esophageal disorders is moving from exclusion-based diagnoses toward multimodal, symptom-oriented physiologic phenotyping.