Colon is an important organ in human body, and colorectal cancer is a disease that occurs in this part. Early colorectal cancer can have some obvious manifestations, as follows: 1. Diarrhea: Most colorectal cancer patients can have diarrhea as the first early symptom of colorectal cancer. The daily number of bowel movements of colorectal cancer patients is obviously increased, mainly for mucus and blood stool, mucus and thick blood stool or loose and thin stool, and the early symptoms of colorectal cancer are accompanied by a feeling of urgency and heaviness, which should be distinguished from bacillary dysentery. If the cancerous tumor of colon cancer protrudes in the rectal cavity and compresses the stool, the stool strips will often become thinner and the shape can be changed, and the early symptoms of colon cancer can be flat. 3. Change of stool habit: It mainly includes the change of stool time and frequency, as well as constipation or unexplained diarrhea. Patients with colorectal cancer may have more frequent stools, but not much stool each time, or even no stool at all, just some mucus and blood, and the feeling of incomplete defecation. These are the early symptoms of colorectal cancer.