Colon cancer is a common gastrointestinal malignancy, and its early symptoms include the following six points: 1. Change in stool habits: right hemicolectomy is characterized by early thin stool, pus and blood, increased number of bowel movements, and alternating diarrhea and constipation when the cancer continues to increase and affects the passage of stool; while left hemicolectomy is mostly characterized by difficulty in defecation, which will continue to worsen with the development of the disease. In addition, if the cancer is in a low position, it may 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 intestinal peristalsis, 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, emaciation, swelling, etc., among which anemia and emaciation are especially important. 4.Abdominal masses: About 50% of patients can find abdominal masses, which are cancer masses or masses infiltrated and bonded with omentum and surrounding tissues, hard and irregular in shape, and some masses can have a certain degree of activity with the intestinal canal, while advanced colon cancer masses 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 manifestations: symptoms of incomplete or complete low-level intestinal obstruction, such as abdominal distension, abdominal pain (distension or colic), constipation or stool closure. Physical examination shows abdominal rumbling, intestinal type, localized pressure pain, and hyper-intense bowel sounds can be heard.