Early detecting and removing of colorectal advanced adenomas can reduce incidence of colorectal cancer. In order to reduce the incidence of colorectal cancer, improve the early diagnosis of colorectal cancer, the investigators conducted this study to explore diagnostic accuracy of fecal immunochemical test in colorectal cancer screening population.

Colorectal cancer accounts for approximately 10% of all annually diagnosed cancers and cancer-related deaths worldwide. With progress of developing countries, it is predicted that the incidence of colorectal cancer worldwide will increase to 2.5 million new cases in 2035. The majority of colorectal cancer is thought to arise from precancerous lesions through the adenoma-carcinoma pathway. Detecting and removing of colorectal advanced adenomas can reduce incidence of colorectal cancer. In order to reduce the incidence of colorectal cancer, improve the early diagnosis of colorectal cancer, the investigators conducted this study to explore diagnostic accuracy of fecal immunochemical test in colorectal cancer screening population.

Inclusion Criteria:

• Adults 50-75 years old

Exclusion Criteria:

• People with history of intestinal surgery;
• People with history of colorectal cancer;
• People with history of inflammatory bowel disease, ischemic enteritis, vascular malformation of intestine or other disease resulting in intestinal tract bleeding;
• People with symptoms including visible rectal bleeding, hematuria, severe and acute diarrhea;
• Pregnancy, lactation or menstrual phase;
• Severe congestive heart failure or other sever disease cause cannot tolerate colonoscopy.

Continuous participants intending to undergo colonoscopy and meet the inclusion and exclusion criteria were enrolled.