In a survey of 2,000 physical examinations performed in an internist''s office, 7 patients with invasive carcinoma of the colon were found. None of the patients in the survey was examined because of large-bowel symptoms. All 7 patients had positive tests for occult blood in at least 1 of 3 stool specimens. This finding led to the preparation of an easier method for multiple stool examination as a routine office procedure. Recent reports have emphasized the limitations of the sigmoidoscope in cancer detection. If a positive reaction is obtained from a multiple stool occult blood test, the patient should be further examined with BaSO4 enema roentgenograms. This is 1 of the best methods for detecting large-bowel cancer during routine well-patient examinations.