Urinary incontinence is a humiliating disability and a common problem in gynaecological clinics. In some centres specialised facilities are avail­ able for its investigation and treatment but in most hospitals the general gynaecologist has to manage this difficult condition. For both generalist and subspecialist it is timely to summarise advances in our knowledge of normal and abnormal micturition. Since 1973 the Royal College of Obstetrician's and Gynaecologists, through its Scientific Advisory Committee, has convened Study Groups on important growth areas in our specialty. The College invites an international panel of leading researchers to participate in a workshop, allowing time for in-depth discussion as well as the presentation of papers. It is hoped that this will produce not only an up-to-date sum­ mary of current knowledge but also a useful interaction between indi­ viduals and between specialties. This book is the result of the 21st Study Group, which was held in October 1989. The participants included urological and colorectal surgeons and a neurologist, as well as scientists and gynaecologists. The meeting began with sessions on basic science and advances in the investigation of the lower urinary tract, then covered voiding diffi­ culties, genuine stress incontinence and detrusor instability, before a final session on the relationship between urinary incontinence and ali­ mentary tract problems. The discussions formed an essential part of the meeting, and it is hoped that the lightly edited versions reproduced here will convey to the reader the stimulating atmosphere of the Study Group.