Colon cancer often has no obvious symptoms in the early stage, and it may show mild symptoms such as abdominal discomfort and change in bowel habits, which are often ignored by patients. In the middle and late stage, patients may experience blood in stool, lumps, weight loss, anemia and other symptoms. However, the staging of symptoms in the early, middle and late stages is not clear, and the occurrence of symptoms is not limited to a particular stage. Symptoms may be more pronounced in the early stage, or they may remain less severe in the middle stage. Therefore, if patients have the following similar symptoms, it is recommended to seek medical diagnosis in a timely manner to avoid delaying treatment: 1. early stage: 1. intestinal irritation symptoms and changes in bowel habits: frequent stools, diarrhea or constipation may occur, diarrhea and constipation may alternate, and abdominal pain and anal swelling may also occur; 2. abdominal discomfort: discomfort symptoms of abdominal distension and abdominal pain may occur in the early stage, and generally the pain is more in the middle and lower abdomen. May appear gradually aggravated. 2.Mid-term: 1.abdominal mass: after the tumor grows to a certain size, a mass can be touched in the abdomen, which can be pushed at the beginning and fixed after invading the surrounding tissues. It is mostly seen in right hemicolectomy; 2. Change of stool trait: tumor breaks and bleeds or invades surrounding tissues causing bleeding, which will cause blood in stool, generally the amount of blood is not much and it is intermittent. If the location of tumor is high, blood mixed with feces may appear jam-like stool. If there is secondary inflammation, the stool may have secretion in it. Late stage: 1. Intestinal obstruction: It is common in the left colon, caused by tumor infiltrating into the intestinal wall, resulting in intestinal stenosis and intestinal obstruction, mostly chronic incomplete intestinal obstruction. It can first appear as abdominal distension, abdominal pain, hyperactive intestinal sounds, constipation, thin stool, etc.; 2. Systemic toxicity symptoms: Most commonly seen in the right colon, because the tumor consumes nutrition in the body and causes chronic long-term bleeding, it can also cause secondary infection, therefore, systemic toxicity symptoms such as anemia, emaciation, fever, weakness, edema, etc.; 3. Local invasion symptoms: it can cause sacral pain, perforation, abdominal abscess, etc.; 4. Metastasis Symptoms: multiple metastases can appear in the late stage of colon cancer, liver metastases can cause liver size, jaundice and ascites; lung metastases can cause cough, shortness of breath, bloody sputum or difficulty in breathing; brain metastases can cause hemiplegia and coma; bone metastases can cause bone pain and claudication. At the end of development, cachexia may appear and cause systemic multi-organ failure.