“…For every 10 people who test positive for faecal occult blood 1 will be found to have a cancer, 3 an adenoma >1 cm, 1 a small adenoma, and 5 a negative examination. If total colonoscopy is undertaken, all lesions detected can be biopsied or removed on the same day, and if the caecum is not reached and lesions have not been biopsied double contrast barium enema can be performed on the same day 7. If double contrast barium enema and flexible sigmoidoscopy are undertaken on the same day, the barium enema cannot precede sigmoidoscopy and polypectomy cannot be performed.…”