The sensitivity and specificity of fecal DNA testing for colorectal cancer screening are 92% and 87%, respectively, but this data is to be validated by prospective randomized controlled studies. Stool DNA testing, a method to screen for colorectal cancer by detecting DNA mutations (e.g. KRAS) through molecular biology analysis and methylation biomarkers associated with colorectal tumors through gene amplification techniques. If a positive result is presented, further colonoscopy is recommended. Colonoscopy is the gold standard for colorectal cancer diagnosis, although it also cannot detect all advanced adenomas and colorectal cancers. Generally, bowel cancer can be initially judged by symptoms, such as bloating, abdominal pain, blood in stool, and change in stool characteristics in the early stage. Once these abnormalities occur, it is necessary to go to hospital for colonoscopy in time.