Esophagogastric junction outflow obstruction (EGJOO) is primarily a manometric diagnosis characterized by reduced relaxation of the esophagogastric junction (EGJ) with at least partially preserved oesophageal peristalsis, which distinguishes it from achalasia, where progradial peristalsis is absent. The definition of EGJOO according to the Chicago classification in the older version 3.0 and the newer version 4.0 differs significantly.
In version 3.0, EGJOO was a purely manometric diagnosis with the possibility of more frequent non-significant artefactual findings. Still, version 4.0 is now a clinical-manometric diagnosis with much more significant benefit and accuracy for practice, able to distinguish non-significant measurement artefacts.
EGJOO is an etiologically heterogeneous diagnosis that may be due to chronic use of opioids and other drugs, mechanical obstruction from various organic causes, or be of functional origin. Treatment depends significantly on the identified cause.
This review details the rationale for refining the diagnosis of EGJOO with Chicago Classification 4.0 and the current algorithm for further management of patients with this diagnosis.