Colorectal cancer lacks specific symptoms in the early stage, and patients have no obvious abnormalities. However, when the mass reaches a certain level, due to the erosion of the tumor, the intestinal mucosa will be stimulated by the foreign body of the mass, and the following symptoms will appear: 1. Abnormal stool habit, increase in the number of bowel movements, as well as a small amount of mucus stool or mucus blood stool, which does not improve after antibacterial and anti-inflammatory treatment, or recurrence after improvement after treatment, the possibility of colorectal cancer should be thought of. 2. If you have a history of mucus stool or diarrhea, but the symptoms suddenly increase and change from the original number of bowel movements and nature of bowel movements, you should also think of the disease. 3, no obvious reason for constipation and diarrhea alternately, no improvement after short-term treatment, in the stomach after barium fluoroscopy did not find abnormalities, should go to the hospital for rectal area examination. 4, defecation effort, the discharge of stool with pressure, grooved, flat, thin strips, etc., must be done rectal examination. Any one of the above four conditions should be examined in hospital in time. Colorectal cancer is easily misdiagnosed. In the early stage, when there is an increase in the number of stools, mucus and pus, it is easy to be misdiagnosed as dysentery, enteritis or hemorrhoids, thus losing the opportunity of treatment. There are many clinical lessons in this regard. Therefore, adults with abnormal bowel movements should be alerted and, if necessary, undergo colonoscopy.