Hardly any other part of the human body is of such interdisciplinary interest as the anal, perianal and rectal region. Gastroenterologists, dermatologists, urologists, general practitioners and surgeons specialising in proctology, phlebology, and coloproctological surgery are involved in this region between the ectoderm, transitional zone, and entoderm. Diagnostic procedures, such as endoscopy, radiology, sonography, manometry, electromyography, and histopathology are even more diverse, in particular where the differential diagnosis of non-neoplastic conditions of the anorectal region is concerned. The Falk Symposium No. 118, held in Freiburg, Germany, on October 1-2, 2000, focused on the morphology and function of the pelvic floor and its dysfunction, radiation damage in proctology, haemorrhoidal complaints, and chronic inflammatory rectal diseases, as well as conditions of the anal and perianal region. These proceedings will be of interest to all research physicians and colleagues working in hospitals or in their own practice who are involved in the diagnosis and treatment of anorectal pathologies.