With the development of science and technology and social progress, people’s living standard has gradually improved, however, the change of living environment and dietary habits have also led to the rising trend of certain diseases that threaten human health. According to the statistics of health-related departments, the incidence of colorectal cancer (usually referring to colon cancer and rectal cancer) has increased significantly in China in the past 20 years. Although the real cause of colorectal cancer is still unclear, its related high-risk factors are gradually recognized by scientific workers, such as excessive diet of animal fat and animal protein, lack of fresh vegetables and fiber foods, and lack of moderate physical activity. Scientific investigations have found that: these high-fat and high-protein foods can increase methylcholanthrene substances in feces, which can induce colorectal cancer; less fiber foods slow down the passage of feces through the intestine and increase the contact time between carcinogenic substances and colorectal mucosa; the reduction of physical activity reduces the consumption of high-fat and high-protein foods in the body. Of course, the development of medical science also brings hope for human beings to detect diseases early and take effective means to treat them. Nevertheless, raising the awareness of the general public about the early symptoms of diseases can help early diagnosis and early treatment of diseases, especially today when there is still a lack of cure for cancer. Feces is the excrement formed after the ingested food is digested and absorbed by a series of digestive enzymes in the human digestive tract. Its main components are water, food residues, undigested cellulose, epithelial cells shed from the digestive tract, mucous membrane fragments, and bile pigments, mucus and digestive juices. The time it takes for food to be excreted from intake to the anus is about 14 hours on average for those who eat a multi-fiber diet and about 28 hours on average for those who eat a less-fiber diet, but the time it takes for food to be transported through the intestine is related to the amount of food and is also influenced by other factors such as mood. Normal feces are cylindrical in shape and about 3-4 cm in diameter. normal feces are yellow in color due to the presence of bile pigments in the feces, but some foods and certain medications also have some effect on the color of the feces. If the stool is deformed and thinner, red or black, or with blood and mucus on the surface, or even pus and blood, coupled with frequent bowel movements, changes in bowel habits and the feeling of incomplete bowel movements, etc., you should be alert to the occurrence of colorectal cancer, and do not think that these symptoms are likely to be the symptoms of hemorrhoids and ignore them.