The study of disease entities as complex as Crohn's dis ease will increasingly require comprehensive knowledge of formerly unrelated areas of the medical sciences. To promote this broad approach, a conference was organized in which geneticists, morphologists, immunologists, and virologists participated as well as clinicians whose work is focused on Crohn's disease. Ample time was given to the presentation of major new findings in each of these areas, and comments were given by the participants in the various sections. This approach yielded many new ideas, because indiv iduals with very different backgrounds were able to address old problems from fresh angles. This volume, published in January, 1981, contains the papers presented dur ing the wor kshop held in June, 1980, in Noordwijk/Leiden, The Netherlands. In addition, we have in cluded the extensive discussions, edited by experts in the field, which followed each presentation. Finally, each main category is followed by a summary of the topic covered as well as many valuable conclusions concerning the significance of recent work and ideas for new directions in research. In the Preface, J.B. Kirsner gives a comprehensive review of the material, and in an Afterword A.J.Ch. Haex deals with a num ber of other aspects. We believe that this volume will be of value to a wide spectrum of scientists and clinicians and that it will help to establ ish the mul tid isciplinary approach to Crohn' s dis ease as the one that should predominate in the future.

This book is a unique work devoted to the subject of disordered defaecation. It contains chapters written by experts in the field of ano-rectal physiology and management of disordered defaecation. The various contributions present personal views and special clinical experience of individuals. There are some personal views which we felt should be commented upon and a few areas where the experience of others has been included into the text. For the sake of completeness of each chapter, a slight overlap in some cases was inevitable. We hope the book will serve as a useful collection of opinions on a subject which until recently has been largely ignored by the medical profession. The editors Major contributors H. O. ten Cate Hoedemaker Department of Surgery, University Hospital, Rijnsburgerweg 10,2333 AA Leiden, The Netherlands G. Coremans Department ofInternal Medicine, University Hospital Gasthuisberg, Here- straat 49, 3000 Leuven, Belgium S. Fasth Department of Surgery II, Sahlgrenska Hospital, S-413 45 G6teborg, Swe- den H. G. Gooszen Department of Surgery, University Hospital, Rijnsburgerweg 10, 2333 AA Leiden, The Netherlands J. A. Gruwez Department of General Surgery, University Hospitals KU, Brusselsestraat 63,3000 Leuven, Belgium M. M. Henry Department of Gastroenterology, Central Middlesex Hospital, Acton Lane, London NWlO 7NS, United Kingdom M. R. B. Keighley Department of Surgery, The General Hospital, Steelhouse Lane, Bir- mingham B4 6NH, United Kingdom J. H. C. Kuypers Department of Surgery, University Hospital St. Radboud, Geert Groote- plein Zuid 14,6500 HB Nijmegen, The Netherlands Ph. B.