Early symptoms of colon cancer: 1. Change of stool habits: right hemicolectomy is characterized by 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 characterized by difficulty in defecation, which will be aggravated 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 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 the onset of chronic appendicitis; 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, paroxysmal abdominal pain, hyperactive bowel sounds, constipation, blood and mucus in stool, etc. 3.Toxic symptoms: Early colon cancer symptoms include anemia, low fever, weakness, emaciation, swelling and other symptoms, especially anemia and emaciation. 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, which is not easy to see with the 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 with the 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 pattern, localized pressure pain, and hyperactive strong bowel sounds can be heard.