The prominent symptoms are abdominal mass, abdominal pain, and anemia. Some patients may have mucus or mucus-blood stools, frequent stools, abdominal distension and intestinal obstruction, but they are far less common than those in the left hemicolectomy. The lumen of the right hemicolectomy is wide, and the primary cancer is often very large when it is detected, and ulcerated masses are common. Unless the cancer directly involves the ileocecal valve, intestinal obstruction is rarely seen. The prominent symptoms of left hemicolectomy are change in stool habit, mucus and blood stool, and intestinal obstruction. The lumen of left hemicolectomy is small, and the primary cancer mostly grows in a circular infiltrative pattern, which easily causes narrowing of the intestinal lumen, so constipation is common. Subsequently, due to the increase of fluid accumulation in the upper end of the narrowed intestinal cavity and hyperactive intestinal peristalsis, diarrhea can appear after constipation, and often alternate between the two. This is one of the early symptoms of colorectal cancer. The prominent symptoms of rectal cancer are blood in stool, change in bowel habits and concomitant symptoms caused by the infiltration of advanced cancer. In situ cancer site is low, the fecal mass is hard, the cancer is easily rubbed by the fecal mass and may cause bleeding, mostly bright red or dark red, which is not mixed with formed feces or attached to the surface of the fecal column and misdiagnosed as “hemorrhoid” bleeding.