With 60000 new cases and approximately 31000 deaths annually the colorectal carcinoma is the second most frequent cause of death due to a tumour in Germany. In over 90% of all colorectal carcinomas the precursors (adenomas) are well known. Moreover the early carcinoma of the colorectum (pT1-carcinoma) has an exceptional benign prognosis. To detect those precursors and early stages effective methods of primary, secondary and tertiary prevention are available.