In order to control the incidence of colorectal cancer, improve the level of early diagnosis and early warning the occurrence of colorectal cancer, it is very necessary for us to explore the threshold value of FIT positive judgment in line with the Chinese population, and further contribute to the establishment of a colorectal cancer screening pathway suitable for Chinese healthy population

Feces were collected for quantitative FIT test. Those with positive results were further examined by colonoscopy. By comparing with pathological results of colonoscopy, the sensitivity, specificity, positive predictive value and negative predictive value of quantitative FIT technology for the diagnosis of colorectal tumors were confirmed.

Inclusion Criteria:

1. Healthy people aged 30 years and planning to undergo colonoscopy;
2. No history of gastrointestinal tumor;
3. No ulcerative colitis or Crohn's disease;
4. No gastrointestinal hemorrhagic disease;
5. No history of gastrointestinal surgery, able to understand and willing to sign informed consent.

Exclusion Criteria:

1. Other serious diseases of the digestive tract, such as Crohn's disease ulcerative colitis;
2. Patients with gastric and esophageal cancer and other malignant tumors;
3. Unable to cooperate after communication;
4. Subjects who have received radiotherapy and chemotherapy;
5. Other researchers believe that they are not suitable for inclusion in this clinical trial, such as mental illness patients, critical patients, pregnant women, illiterate minors, cognitive impairment PI, students of the researcher, PI, affiliated research units of the co-investigator or employees of the sponsor, etc

Healthy physical examination person over 30 years of age