Lay summary
Each month, 2,500 New Zealanders undergo a colonoscopy because of symptoms of colorectal (bowel) cancer. Unfortunately, Health New Zealand's colonoscopy capacity is highly stretched, resulting in long delays for most people. For people with colorectal cancer (2% of the total), these delays can significantly compromise their chances of surviving the disease. We have developed a prototype blood test which will be able to be used to identify the people on these waiting lists who are most likely to have cancer and require an urgent colonoscopy and prompt treatment. This research will clinically validate that test. As we build data on the test's performance, we anticipate it will also be able to be used as an alternative to colonoscopy for many people, resulting in cost savings and reduced waiting lists.