This multiauthor book is an update on the science and surgery of malformations of the rectum and anus. It carries on Douglas Stephens’ book “Congenital Malformations of the Rectum, Anus, and Genito-urinary Tracts” published in 1963. This first book, which deals exclusively with malformations of the lower end of the digestive and urogenital tracts, was based on fundamental studies on paediatric pathology, surgery and surgical anatomy performed at the Department of Surgical Research of the Royal Children’s Hospital, Melbourne, Victoria, Australia. Until today these studies have represented the embryological and pathoanatomical basis of our knowledge in the diagnosis and treatment of anorectal malformations (ARM). In 1971 Douglas Stephens and Durham Smith published the first update of their book, called “Ano-Rectal Malformations in Children”. It became the standard work for ARM for the following 17 years. In 1984 an international workshop took place at the Wingspread Convention Center, Wisconsin, USA, hosted by the Department of Surgery, Chicago Children’s Memorial Hospital, where Douglas Stephens worked at that time. The chief objects of that meeting were an update of the approximately 170 years of experience with modern treatment of ARM and to set standards for the classification and treatment of this malformation. At the end of the conference the so-called Wingspread classification was settled, technical details for abdominal, sacral, and perineal approaches were proposed and the great variety of ARM listed again. The results of the Wingspread meeting were finally published by Stephens and Smith in 1988 with support of the March of Dimes Birth Defects Foundation at Alan R. Liss, New York . The Wingspread classification of ARM divided ARM into high, intermediate, and low types and correlated the individual underlying pathoanatomy with the appropriate surgical procedures. This meant, roughly speaking, that a perineal approach should be performed for low-type, a sacral approach for intermediate-type, and an abdominosacro-perineal pullthrough for high-type malformations. These Wingspread considerations continue to have great influence on the diagnosis and therapy of ARM.