The rectosigmoid, or retrosigmoid juncture, is that part of the bowel opposite the reflection of the peritoneum in the lowermost portion of the pelvic cavity. Clinically the terminal inch (2.5 cm.) of the sigmoid flexure of the colon and the uppermost inch of the rectum are considered as composing it. Next to the stomach the rectum is the most common site of malignant disease of the gastrointestinal tract. It is generally accepted that rectal carcinomas make up about 4 per cent of all carcinomas and that about 80 per cent of intestinal carcinomas appear in the rectum. Rankin and his associates1 stated:
We believe that most carcinomas of the rectum are at the rectosigmoid juncture, that the next point of frequency is in the ampulla of the rectum, and that the site of least frequency is the anal canal and the lower five or six cm. of the rectum.
ARNOLD HR. RESECTION OF THE CARCINOMATOUS RECTOSIGMOID JUNCTUREWITH REESTABLISHMENT OF INTESTINAL CONTINUITY: PRELIMINARY REPORT. Arch Surg. 1939;38(6):1004-1013. doi:10.1001/archsurg.1939.01200120027003