The Chicago Classification v4.0 (CCv4.0) is the updated classification scheme for esophageal motility disorders using metrics from high-resolution manometry (HRM). A key feature of CCv.4.0 is the more rigorous and expansive protocol that incorporates single wet swallows acquired in different positions (supine, upright) and provocative testing, including multiple rapid swallows and rapid drink challenge. Additionally, solid bolus swallows, solid test meal, and/or pharmacologic provocation can be used to identify clinically relevant motility disorders and other conditions (eg, rumination) that occur during and after meals. The acquisition and analysis for performing these tests and the evidence supporting their inclusion in the Chicago Classification protocol is detailed in this technical review. Provocative tests are designed to increase the diagnostic sensitivity and specificity of HRM studies for disorders of esophageal motility. These changes attempt to minimize ambiguity in prior iterations of Chicago Classification, decrease the proportion of HRM studies that deliver inconclusive diagnoses and increase the number of patients with a clinically relevant diagnosis that can direct effective therapy. Another aim in establishing a standard manometry protocol for motility laboratories around the world is to facilitate procedural consistency, improve diagnostic reliability, and promote collaborative research.

Chicago Classification v4.0 (CCv4.0) is the updated classification scheme for esophageal motility disorders using metrics from high-resolution manometry (HRM). Fifty-two diverse international experts separated into seven working subgroups utilized formal validated methodologies over two-years to develop CCv4.0. Key updates in CCv.4.0 consist of a more rigorous and expansive HRM protocol that incorporates supine and upright test positions as well as provocative testing, a refined definition of esophagogastric junction (EGJ) outflow obstruction (EGJOO), more stringent diagnostic criteria for ineffective esophageal motility and description of baseline EGJ metrics. Further, the CCv4.0 sought to define motility disorder diagnoses as conclusive and inconclusive based on associated symptoms, and findings on provocative testing as well as supportive testing with barium esophagram with tablet and/or functional lumen imaging probe. These changes attempt to minimize ambiguity in prior iterations of Chicago Classification and provide more standardized and rigorous criteria for patterns of disorders of peristalsis and obstruction at the EGJ.