The purpose of this book is an examination of the anatomy and motility of the pylorus in view of many divergent views. Anatomical findings of Cunningham, Forssell and Torgersen et al. are discussed and integrated with radiological forms of movement. It appears that the pyloric ring is not a "sphincter" but that it forms part of a more intricate sphincteric mechanism. Evidence for a sphincteric cylinder is presented. Its cyclical activity may open and close the aperture and result in propulsion and retropulsion.The role of gastroscopy, manometry, ultrasonography and radionuclides in pyloric...