Colonoscopy findings according to the test results

	Positive G-FOBT	Hb level (I-FOBT) (ng/ml) 20–50
Hb, haemoglobin; G-FOBT, guaiac faecal occult blood test; I-FOBT, immunochemical faecal occult blood test.
No neoplasia	108	167
Adenoma,10 mm	30	67
Advanced neoplasia	53	50
Adenoma >10 mm or high grade dysplasia,10 mm	39	48
Invasive cancer	14	2