1.Change of stool habit: In right hemicolectomy, the stool is thin, with pus and blood, and the number of bowel movement increases in the early stage, and when the cancer continues to increase and affects the passage of stool, alternating diarrhea and constipation may occur; while in left hemicolectomy, the stool is difficult to pass, and it keeps getting worse with the development of the disease. In addition, if the cancer is in a low position, it can also cause poor defecation and a feeling of urgency and heaviness. 2.Gastrointestinal tract symptoms: manifested as abdominal distension, discomfort or indigestion-like symptoms. In the case of right hemi-colon cancer, it is mostly abdominal pain and discomfort or hidden pain. At the beginning, it can be intermittent, but later turns into continuous, often located in the right lower abdomen, much like chronic appendicitis attack; while in the case of left hemicolectomy, it is mostly manifested as sudden onset of obstruction, abdominal cramps, accompanied by abdominal distension, hyperactive bowel movement, constipation and obstructed exhaustion, or chronic obstruction symptoms such as abdominal distension, discomfort, paroxysmal abdominal pain, hyperactive bowel sounds, constipation, blood and mucus in stool, etc. 3.Toxic symptoms: Early colon cancer symptoms also include anemia, low fever, weakness, wasting and swelling, especially anemia and wasting. 4.Abdominal mass: About 50% of patients can find abdominal mass, which is a mass of cancer or infiltrated and bonded with omentum and surrounding tissues, hard and irregular in shape, and some masses can have a certain degree of activity with intestinal canal, while advanced colon cancer can be fixed due to cancer infiltration. 5. Blood or mucus in stool: In right hemicolectomy, the bleeding is small and fully mixed with stool due to peristaltic movement of colon, so it is not easy to be seen by naked eye, but the occult blood test is often positive; while in left hemicolectomy, the bleeding and mucus are not mixed with stool, and about 1/4 patients can observe blood and mucus in stool by naked eye. 6.Intestinal obstruction manifestation: incomplete or complete low-level intestinal obstruction symptoms, such as abdominal distension, abdominal pain (distension or colic), constipation or stool closure. Physical examination reveals abdominal rumbling, intestinal type, localized pressure pain, and hyper-intense bowel sounds can be heard.