now that helicobacter pylori is generally accepted as a key aetiological agent in gastric cancer as well as the main agent in peptic ulcer, it can claim to be the most important new discovery in clinical gastroenterology of the last decade, and yet there is no up-to-date book available on the subject that is designed primarily for the clinical gastroenterologist. this book aims to fill that niche. it should also be of interest to the basic scientist, to those providing a clinical laboratory service (microbiologists and histopathologists), and to epidemiologists and others involved in clinical research.