[Endoscopic diagnoses in patients with positive Hemoccult-test: critical consideration and negative Hemoccult-test (author's transl)].

Totally 170 patients with positive (n = 29) and with negative Hemoccult-test (n = 141) were examined by coloscopy. There were 29.0% false-negative Hemoccult-test results (carcinomas 5.6%, polyps 23.4%). Almost all patients with a endoscopically diagnosed carcinoma or polyp of the large bowel had clinical signs. It is concluded, that the Hemoccult-test is indicated only in patients, who do not show clinical symptoms, and that a negative Hemoccult-test result does not exclude a tumor of the large bowel.