title: "Chicago classification" should be challenged in the diagnosis of achalasia: heterogeneity of achalasia.
authors.affiliation: Institute for Digestive Research, Soonchunhyang University, College of Medicine, Seoul, Korea.
authors.forename: Tae Hee
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Soonchunhyang University, College of Medicine, Bucheon, Gyeonggi-do, Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Hong