The purpose of this book is to explain the current state of the art in radiological examination, interpretation, and understanding of colonic disease. The radiologic aspects of colon disease are combined here with clinical information to serve both beginners and advanced students. Major emphasis has been placed on technique for those radiologists, residents, and technologists first undertaking modern gastrointestinal radiographic techniques. The essentials of technique are stressed so that the reader obtains a clear understanding of colon disease based on sound practical information. We believe this book is a thorough and practical text of particular interest to clinical radiologists and gastroenterologists in their everyday practice, and also for teachers, residents and medical students. Digital examination and sigmoidoscopy are the first procedures in examination of the colon. Then, the radiologic examination is the next most important procedure. Endoscopy and biopsy play a compli­ mentary role to the radiological examination. The barium enema reveals quickly and early the overall status of the colon and it can then guide endoscopy and biopsy together with subsequent treatment. Surely, if the lesion is not detected our clinical, radiologic, endoscopic, and therapeutic skills are of no use.