Sato H, Fujiyoshi Y, Abe H, Shiwaku H, Shiota J, Sato C, Sakae H, Ominami M, Hata Y, Fukuda H, Ogawa R, Nakamura J, Tatsuta T, Ikebuchi Y, Yokomichi H, Terai S, Inoue H.  Development of Dilated Esophagus, Sigmoid Esophagus, and Esophageal Diverticulum in Patients With Achalasia: Japan Achalasia Multicenter Study.  J Neurogastroenterol Motil 2022;28:222-230.  https://doi.org/10.5056/jnm21188