In 2012, 140 000 women and men 50-74 years old were drawn by randomization from the Central Population Registry, and during a six-year period invited to participate.
Those drawn for flexible sigmoidoscopy had one screening round, while the test for occult blood is repeated every second year for up to four rounds.
About 10 per cent of those tested with either the one or the other method, will be recommended endoscopic examination of the whole colon (colonoscopy) – not only the lower part, which is examined by flexible sigmoidoscopy.
Screening is first and foremost for those who do not have symptoms. If you have symptoms originating from the colon, lasting longer than 4-6 weeks, you should contact your doctor and not wait to see if you get an invitation for the screening project.