This book is an extraordinary achievement by Jonathan Halevy. To condense the material of three major gastrointestinal textbooks would be triumph enough, but to add a distillate of the contents of ten journals, from 1980 to 1985, requires Herculean vigor. To reorganize all the material under headings which extract concise "facts" from wheat and chaff requires a passionate interest in pa tients together with an understanding of physiology. Fortunately, Jonathan Halevy has just the right combination of clinical and lab oratory interest for him to select the details of what is important. Such...