The incidence of colorectal cancer is most often rectal cancer, accounting for 56%——70%, with an average of 60%. Rectal cancer has 88.5% of blood in the stool, followed by changes in stool properties, mucus peptones, etc. Therefore, a considerable part of rectal cancer can be detected early, but the actual clinical situation is far from optimistic, according to statistics, the detection rate of early rectal cancer in China is only 2% to 5%, and rectal cancer has an average of one year from the appearance of clinical symptoms to diagnosis. One year is not long in a person’s life, but it is too long for a tumor, because if the tumor of rectal cancer is confined to the intestinal wall, the 5-year survival rate of treatment can be more than 80% at this time, but the survival rate of 5 years beyond the intestinal wall is less than 40%. Therefore, it is important to pay attention to the early detection, early diagnosis and early treatment of rectal cancer to improve its long-term survival rate. Why is this so? There is negligence of doctors and carelessness of patients themselves, which eventually lose the opportunity of early treatment. The first symptom of rectal cancer, the most common symptom is blood in stool, blood in stool, bright red or dark red blood, the amount is usually not much, the Chinese have a saying that nine out of ten people have hemorrhoids, many middle-aged and elderly people have hemorrhoids, and a common manifestation of hemorrhoids is blood on the surface of stool or blood dripping or splashing after stool. So when there is bleeding or blood in the stool, people often think it is caused by hemorrhoids, so they don’t pay attention to it, and many non-oncology doctors often think so too. In fact, as a doctor, many rectal cancers could have been diagnosed at an early stage, because in rectal cancer, about 80% of the lesions are located in the lower part of the rectum, which is very close to the anus, so the doctor can mostly find the problem by doing anal finger examination. Some of them are not diagnosed until the occurrence of intestinal obstruction. Similar tragedies are staged almost every day, and there are many reports in this regard in the literature. A second-rate hospital reported that among the 20 cases of rectal cancer admitted in 1995, none of them were early-stage rectal cancer. Therefore, middle-aged and elderly people or even young people, when there is blood in the stool, do not be satisfied with the diagnosis of hemorrhoids, that is, had hemorrhoids before, should also go to check. In this regard, the doctor’s responsibility is a bit greater than the patient’s, so the patient should look for a specialist during the consultation, and you can tell if the doctor is a responsible doctor by whether or not he has given you an anal finger test. The second early manifestation of rectal cancer that can be easily misdiagnosed is pus and blood in the stool, which is often treated as dysentery (the feeling of not being able to finish the stool, anal swelling, and always wanting to defecate). Due to the ulceration of the rectal surface mass, or combined with infection, the mucosal necrosis and stool mixed together, the symptoms are the same as chronic dysentery, and the stool is checked for pus cells, red blood cells and phagocytes, and a little antibiotic can be used for a while, which makes it easy for patients and doctors to treat it as dysentery, and the longest misdiagnosis in the literature can be 1-2 years. It is understandable that when there is pus and blood in the stool, it should be treated as dysentery initially, because after all, dysentery is the majority and tumor is the minority in this case, but it is not right to treat it as dysentery for months or even half a year. Therefore, if it is a pus and blood stool in the non-dysentery season, a long untreated dysentery we should think about the possibility of rectal cancer and should do some appropriate tests. It may not be cancer in the end, but we should have this string in our brain. The common first symptoms of colon cancer are abdominal pain, abdominal mass, diarrhea, etc., but when these symptoms appear, they are usually not early, so the disease characteristics of colon cancer are not as obvious as those of rectal cancer, especially the right hemicolectomy, which mainly relies on colonoscopy and barium enema, both of which require clean enema, which is somewhat troublesome, but very meaningful for diagnosis, so as a patient, when the doctor asks you to check Therefore, as a patient, when the doctor asks you to take the test, you should cooperate with the doctor and not refuse because of the trouble. In addition, fecal occult blood test is also a useful and easy test, once the occult blood is positive, the cause should be further investigated. Colon cancer should be considered in case of unexplained anemia. Therefore, once anemia occurs, especially when there is no obvious blood loss (such as excessive menstruation in women), it should be taken seriously. There are three major causes of anemia caused by non-nutrition and non-blood loss: gastrointestinal cancer, chronic kidney failure, and blood diseases. In middle-aged and elderly people, cancer is especially common. The author has treated many patients who were found to be anemic during physical examination and then found to have cancer. In chronic anemia, the patient may have no symptoms, so a simple blood and fecal routine is important from this point of view, even if you cannot have a regular physical examination.