Dr. E. R. Cullinan: Classification of Chronic Diarrhoea. Introduction.-Chronic diarrhoea (non-tropical) is an important but too often neglected symptom. Lengthy lists in textbooks of its possible causes are many, but papers analysing cases seen in practice are few. Twenty-five years ago Ryle (1924) described various types of chronic diarrhoea in 54 cases seen in this country. His classification was largely anatomical. More recently Bockus (1944) gave an etiological classification of cases seen in Philadelphia. He put the first four causes of diarrhoea in order of frequency as being diarrhoea of nervous origin, chronic ulcerative colitis, carcinoma of the colon, and gastrogenous diarrheea. The following is an analysis of 99 patients whose presenting and often sole symptom