Chicago Classification of esophageal motility disorders: Past, present, and future.

The Chicago Classification (CC) is a dynamic, evolving classification scheme created by a diverse group of international esophageal experts. Its application has transformed the way esophageal motor data are used to define motility disorders, each iteration seeking to advance, simplify, and standardize the way clinicians worldwide diagnose esophageal dysmotility. The most recent update, CC version 4.0 (CCv4.0), emphasizes the importance of clinical context and distinguishes clinically relevant, conclusive manometric diagnoses from irrelevant manometric observations. Future iterations of CC may refine the classification of spastic esophageal disorders and incorporate machine learning and physics-based modeling to improve metrics.