The primary objective of this study is to evaluate the sensitivity of the fecal protein dual-index test reagent for the detection of colorectal cancer (CRC).

The project uses fecal hemoglobin and transferrin dual-index combined with reagents that can be self-tested at home (referred to as fecal protein dual-index detection reagents), combined with colorectal cancer risk factor questionnaires, to carry out colorectal cancer screening in people of specific ages in the city, aiming to achieve early screening, early diagnosis and early treatment, and evaluate the effect of fecal protein dual-index detection reagents in early screening of colorectal cancer, so as to provide a scientific basis for optimizing the national screening program.

Inclusion Criteria:

1. Subjects aged 45-74 years at time of consent
2. Have not had gastrointestinal resection

Exclusion Criteria:

1. Previous history of colorectal cancer
2. Patients who have been confirmed to have other malignant neoplastic diseases of the digestive system
3. Patients with severe heart, brain, lung disease or liver and kidney dysfunction or insufficiency
4. Those with severe mental disorders and language communication disorders
5. History of contraindications to colonoscopy
6. Pregnant women

Single cohort of patients aged between 45 and 84, with no known high risk features, undergoing routine colorectal cancer screening as standard of care.