[Practical experiences with the stool test for occult blood].

In the light of the literature and 10 years personal experience, the following conclusions are drawn: 1. Screening for colon cancer with Hemoccult works and is practicable. 2. Asymptomatic and unknown symptomatic cancers are detected. 3. These cancers are predominantly in an early stage (70% at Dukes A and B). 4. Large adenomatous polyps, i.e. precancerous neoplasias, can also be detected. 5. One-time testing may miss 15-20% of cancers and 40-50% of adenomatous polyps (depending on their size!). 6. Repeated screening during the 2 years before diagnosis lowers these false-negative figures to less than 10% in carcinomas and less than 30% in large polyps. 7. Screening for colon cancer should be started at age 45 and thereafter repeated annually.