In a preliminary report1 before the American Proctologic Society, at the Detroit meeting, June, 1916, on "Anatomic and Bacteriologic Findings of the Ano-Rectal Region," I called attention to the sinuses and diverticula in this region. It was announced that cocci, and other forms of bacteria, had been found in their walls and contents, and the possible relation to focal infections was pointed out. Since I desire to emphasize the relations between these sinuses and diverticula, and anal and rectual fistula, the present communication is necessarily elementary and textbook-like in character.
A fistula is an infected artificial channel between the skin and the serous or mucous membrane of a normal cavity, or between two normal cavities. It has two or more openings. A sinus, often confounded with a fistula, is an infected artificial channel connecting the skin or mucous membrane with an abnormal cavity. It has, as a rule, one