Methods of screening of colorectal cancer are necessaries, because the increasing number of new cases. The faecal occult test(fobt) is considered good for populations with low risk. The goal of this paper is to determine the incidence of neoplasic or pre neoplasic lesions in patients with fobt positive or negatives and correlate with the results of the colonoscopies. Sixtie seven patients were submited to colonocopies and fobt.the main indications were abddominal pain, familial history of cancer and modification of bowel habits. Thirty seven patients had negatives fobt and thirty positives.twenty two colonoscopies were normal. Others findings were polyps, ulcerative colitis, diverticular disease and one tumor. Sensitivity was 46.7% and specificity 59.1%. Positive predictive values were 70% and negative 35.1%. Considering only malignant or pre malignant lesions the sensitivity was 76.5% and specificity 66%, positive predictive values were 43.3% and negative 89.2%. In conclusion the faecal occult blood test for his low cost and non invasive is a good method of screening after forty years of age.
occult blood; intestinal neoplasm; intestinal polyps; secondary prevention; colonoscopy
