Colorectal cancer, commonly known as colorectal cancer, is a cancer that occurs in the colon. Colon is a very important section of intestinal tube in human body, its function is to absorb water and some other substances from the food residues digested and absorbed by small intestine, and eventually turn these residues into feces and finally excreted from the body. The development of colon cancer is related to many factors, such as dietary habits, genetics, and inflammation of the colon. The high incidence of colon cancer in economically developed regions is mainly related to their dietary structure, the so-called “Western cultural diet”, which is high in animal protein, high in fat, and too fine in diet, such as beef, less fiber and refined rice and noodles. This is mainly because the fat and its decomposition products in food may have carcinogenic or synergistic carcinogenic effects. Diet with less fiber can reduce the amount of stool and make the stool pass through the intestinal tract for a significantly longer time, so that the concentration of synergistic carcinogens in the stool increases and the contact time with the colonic mucosa is significantly prolonged, and the long-term contact between carcinogens and the colonic mucosa may lead to cancer. Therefore, we advocate eating more vegetables and fruits containing fiber, such as spinach, celery, fruits, etc., in order to keep the stool smooth and reduce the contact time between carcinogens in stool and colonic mucosa; reduce the intake of fat and animal protein in food. It can reduce the carcinogen production and carcinogenic effect of their decomposition products to reduce the potential risk of colon cancer development. Although colorectal cancer can develop at any age, more than 90% of cases are older than 40 years old. Therefore, it is usually recommended that people over the age of 40 should begin routine medical examinations to detect possible cancer in a timely manner. Although we do not know the cause of colon cancer, the available evidence suggests that almost all colon cancers originate from colon polyps. These polyps are new organisms in the intestinal mucosa that may be initially small, only a few millimeters, and are benign lesions; they may grow and become malignant and cancerous. Therefore, colonoscopic removal of benign polyps that are still very small is one of the effective measures that can prevent cancer. The most common symptoms of colon cancer are blood in the stool and changes in bowel habits, such as constipation and diarrhea. When patients experience abdominal pain and weight loss, it often indicates that the disease may have progressed. There are several ways to screen for colon cancer, including chemical tests for blood in the stool, flexible sigmoidoscopy, colonoscopy (an illuminated tubular device that can examine the lower intestine), and barium enemas. You should talk to your physician about which test is best for you. There are many ways to treat colon cancer, but a combination of treatment measures, mainly surgery, must be used. For a complete cure, almost all colorectal cancers require surgical treatment. Sometimes radiotherapy and chemotherapy are also required. About 80-90% of colorectal cancer patients who are detected early and treated can be cured. The chance of cure for colorectal cancer detected later decreases to 50% or less. It should be noted that colon cancer can be prevented. Screening is the most important step in the prevention of colon cancer. Colonoscopy is a good way to prevent colon cancer as it can carefully examine the entire intestine, find polyps, and remove most of them at the same time as the examination. Hemorrhoids do not cause cancer, although hemorrhoids may present with symptoms similar to those of colon polyps or cancer. If you experience such symptoms, you should be examined and evaluated by your doctor. One final reminder is to be sure to pay attention to your bowel habits. Any new changes such as persistent constipation, diarrhea and blood in the stool should be seen by your doctor.