Colorectal cancer, including colon cancer and rectal cancer, is a kind of cancer with hidden early symptoms and can be easily confused with many diseases. Colorectal cancer grows slowly, has a long time limited to localization, and can be surgically cured by early detection. Some data show that about 30% to 40% of bowel cancer patients are misdiagnosed due to the negligence of doctors and patients themselves. Nowadays, the incidence rate of colorectal cancer worldwide is increasing at an average annual rate of 2%, while the survey in Shanghai shows that the incidence rate of colorectal cancer in China is increasing twice as fast as the world average, reaching an average annual rate of 4%. The common manifestations of early colorectal cancer are as follows: 1. Blood in stool: Early lesions of colorectal cancer are limited to mucous membrane, which may be asymptomatic or only have changes in bowel habits. When the tumor grows to a certain extent, blood in stool can appear, which is mostly light in color and adheres to the surface of stool. Red blood cells can be found in the stool microscopy and the fecal occult blood test is positive. Patients with bloody stool or continuous positive fecal occult blood should first consider the possibility of colorectal tumor and should undergo further relevant examinations; 2.Mucus stool and pus stool: when the cancer ruptures, the stool often contains bright red or dark red blood and mucus, and the feces and blood are mixed; 3.Change in defecation habit: the number of stools changes from once a day to two or three times a day, and there is a feeling of incomplete stool after each stool; 4.Diarrhea Alternation of diarrhea and constipation: if there are symptoms such as alternation of diarrhea and constipation, it may be because the growth of cancer tumor affects the normal physiological function of intestine, and the possibility of cancer should be considered; 5. Abdominal pain and bloating: patients with intestinal cancer will have abdominal bloating and abdominal pain due to intestinal obstruction, among which the incidence of abdominal pain is higher than that of abdominal bloating. The location of pain is mostly in the middle and lower abdomen, and the degree of pain varies, mostly hidden pain or distension; 6.Anemia and wasting: with the progress of disease, patients may develop chronic wasting symptoms, such as anemia, wasting, weakness and fever, or even cachexia, and often accompanied by fatigue and unexplained sudden weight loss, related to blood in stool, insufficient intake and excessive consumption. When the above manifestations are present, colorectal cancer should be considered as a possibility, and it is better to go for colonoscopy, which is an effective means for early diagnosis of colorectal cancer. In recent decades, the concept and technology of surgical treatment for colorectal cancer have been developed significantly, and the emergence of platinum oxalate, oral fluorouracil and targeted drugs have improved the prognosis of colorectal cancer patients, and more and more patients have achieved long-term tumor-free survival.