[Value of the study of occult fecal blood with Hemoccult II in 211 symptomatic patients controlled by total colonoscopy]. / Validità della ricerca del sangue occulto fecale con Hemoccult II in 211 pazienti sintomatici controllati mediante colonscopia totale.

211 possibly neoplastic patients were given total colonoscopies after Hemoccult II test. The purpose of the experiment was to judge the value of occult faecal blood tests in the diagnosis of colonic neoplasias. Positive test results were obtained in 52 of whom 5 were found to have carcinomas and 17 polyps. Negative Hemoccult II results were produced in 159 patients of whom 6 had carcinomas and 54 polyps. All carcinoma patients with positive Hemoccult II results had rectal bleeding, 50% of those with negative tests results. Among polyp patients, 53% of those with Hemoccult II positive reported rectal bleeding, 60% of those with negative test results. Thus Hemoccult II is shown to be insufficiently sensitive to be of much value in mass screenings. It is suggested that a more sensitive test should be used for surveys of occult faecal blood.