shelf manual for the gastroenterologist and the staff of gastrointestinal investigation units. Special thanks are due to the nursing staff of the Day Ward, Bishop Auck­ land General Hospital; Mr P. Grencis, Medical Photographer; Dr S. Desai, Radiologist; and Amanda Gallagher who typed the manuscript. Malcolm C. Bateson Ian A. D. Bouchier 1988 xu CHAPTER 1 Intubation The passage of various forms of nasogastric, duodenal and intestinal tubes is basic to many of the diagnostic procedures performed in the gastrointestinal system. Method Whenever possible the patient's fullest co-operation should be obtained. If the patient is taking any drugs which might influence the test to be under­ taken these should be discontinued.