Since the early symptoms of colon cancer are not very obvious, it is easy to be overlooked, which eventually leads to serious consequences, but some early symptoms can be found if we pay attention to them. Early symptoms of colon cancer mainly include abdominal mass, change of stool habit, stool with blood or mucus. About 50% of colon cancer patients can find abdominal masses, which are cancer masses or masses bonded with omentum and surrounding tissue infiltration, hard and irregular in shape, and some masses can have certain mobility with intestinal canal, while advanced colon cancer masses can be fixed due to cancer infiltration. In the case of right hemicolectomy, the early stage is characterized by thin stool, pus and blood, increased frequency of defecation, and alternating diarrhea and constipation when the cancer continues to increase and affects the passage of stool; while in the case of left hemicolectomy, it is mostly characterized by difficulty in defecation, which worsens with the development of the disease. In addition, if the cancer is in a low position, it may also cause poor bowel movement and a feeling of urgency. In the case of right hemicolectomy, the bleeding is small and fully mixed with feces due to peristaltic movement of the colon, so it is not easy to be seen with the naked eye, but the occult blood test is often positive; while in the case of left hemicolectomy, the bleeding and mucus are not mixed with feces, and about 1/4 of patients can observe fresh blood and mucus with the naked eye in the feces. The manifestation is abdominal distension, discomfort or, indigestion-like symptoms. In the case of right hemi-colon cancer, it is mostly abdominal pain and discomfort or vague pain. It may be intermittent at the beginning, but later turns into continuous, often located in the right lower abdomen, much like chronic appendicitis attack; while in left hemicolectasis, it is mostly manifested as sudden onset of obstruction, abdominal cramps, accompanied by abdominal distension, hyperactive bowel movement, constipation and obstructed venting, or chronic obstruction symptoms such as abdominal distension, paroxysmal abdominal pain, hyperactive bowel sounds, constipation, blood and mucus in stool, etc.