Early stage colorectal cancer patients may have no obvious symptoms, and some patients are mainly characterized by changes in bowel habit and fecal character. Colorectal cancer, including colon cancer and rectal cancer, the risk factors of this disease include colorectal adenoma, inflammatory bowel disease, fecal occult blood positivity, family history of colorectal cancer, long-term smoking, excessive alcohol consumption, obesity, activity, less activity, age >50 years old and so on. Early symptoms of colorectal cancer are usually dominated by changes in defecation habit and fecal character, which are mainly reflected in alternating diarrhea and constipation, as well as thinning of fecal character. In clinic, right colorectal cancer mostly manifests systemic symptoms, such as anemia and abdominal mass, while left colorectal cancer mostly manifests blood in stool, diarrhea, constipation and intestinal obstruction. If there are clinical symptoms related to colorectal cancer, it is recommended to go to regular hospitals to avoid delaying the condition.