The primary objective is to determine the diagnostic sensitivity and specificity of the newly developed liquid biopsy based multiomics Colorectal Cancer (CRC) screening test (CRC-Appareo) for detecting advanced neoplasia (including colorectal cancer and advanced adenomas) in high risk patients and patients with confirmed CRC, using colonoscopy as the reference method. The secondary objective is to compare the screening performance of the multiomics Colorectal Cancer (CRC) screening test with commercially available FIT (Fecal Immunochemical Test) assay in detecting advanced neoplasia.

The study will be carried out in 5 hospitals throughout China. Patients who are at high risk of developing CRC or confirmed CRC and willing to conduct colonoscopy examination will be asked to collect blood prior to bowl preparation for multiomics CRC screening test which using Reduced Representation Bisulfite Sequencing (RRBS) technology to obtain multidimensional variation information on cell-free DNA (cfDNA) methylation, end sequence, fragment size distribution, and copy number variation in the blood, and integrate analysis through machine learning algorithms to accurately assess the risk of colorectal cancer and advanced adenoma. and will be asked to collect stool sample for commercially available FIT assay. Colonoscopy and histopathologic examination are used as reference. The diagnosis information of each sample was blind to the participants who conduct the multiomics profiling, as well as the informatics who perform the integrate analysis.

Inclusion Criteria:

Willing to provide written consent Able to provide blood and stool samples

For high risk CRC screening group:

Scheduled for colonoscopy voluntarily or by physician prescription

CRC high risk profile as defined below:

History of FIT positivity Family history of CRC Any of two of the following clinical symptoms: chronic constipation/diarrhea, stool with mucous, chronic appendicitis, chronic bilary track diseases, mental stress

For CRC group:

Confirmed CRC patients No prior treatment with chemotherapy, radiotherapy, and prior to any surgical procedures

Exclusion Criteria:

Unwilling to provide blood samples FAP (familial adenomatous polyposis), Crohn's disease, ulcerative colitis Prior history of colonoscopy within the past 5 years and removal of lesions History of CRC other conditions deemed not suited for the study by investigators

Subjects with high risk of developing CRC and CRC patients