Large bowel segment lengths and the distribution of colorectal cancer.

Data was obtained on the average length and variability of each anatomical segment and for the whole of the large bowel from 50 patients examined by air contrast barium enema X-ray examination. Results were validated by measurements of the colon and rectum removed at autopsy in ten patients. Large bowel segment measurements from barium enema X-ray examinations were shown to be a valid basis for determining the average in vivo lengths of segments. The use of descriptive terms based on the anatomical location of colorectal carcinoma should be replaced by a more exact method of defining site distribution when recording and reporting the distribution of carcinomas and operative series and for teaching purposes.