Site-specific distribution of large-bowel adenomatous polyps. Emphasis on ethnic differences.

The anatomic distribution of adenomatous polyps occurring in the large intestine of 98 consecutive patients was studied. Fifty-two of the patients were black and 46 were white. Seventy-nine percent of lesions in whites were found in the distal colon and rectum, whereas in blacks this occurred in only 47 percent. The difference was significant (P less than .01). Black patients also displayed a greater frequency of synchronous polyps and had a higher incidence of previous colorectal polyps. The findings suggest that the total colonic surveillance is essential in black patients to adequately screen for large-bowel neoplasia.