Rectal cancer is a common malignant tumor in China, accounting for the fourth place of malignant tumors in China, and there is a rising trend. However, in recent decades, with the improvement of people’s living standard and the change of diet structure, the proportion of colon cancer is also increasing gradually. What are the clinical symptoms of rectal cancer that people care a lot? Clinical symptoms of rectal cancer vary according to the growth site: 1. Clinical manifestations of right hemi-colon cancer: (1) abdominal pain, 70% to 80% of patients with right hemi-colon cancer have abdominal pain, mostly hidden pain. (2) Anemia, caused by necrosis, shedding and chronic blood loss of cancer foci, 50%-60% of patients have anemia such as pallor and weakness. (3) Abdominal mass. Abdominal mass is also a common symptom of right hemi-colon cancer, and it is not common to see abdominal mass with obstruction at the same time. Clinical manifestations of left hemicolectomy cancer: (1) Blood in stool, mucus and blood in stool, more than 70% can have blood in stool or mucus and blood in stool. (2) Abdominal pain, about 60% of which may be vague, or abdominal colic when obstruction is present. (3) Abdominal mass, about 40% of the patients can palpate the left lower abdominal mass. Clinical manifestations of rectal cancer: (1) rectal irritation symptoms, frequent bowel movements, change in bowel habits, feeling of falling in the anus before defecation, urgency and heaviness, feeling of incomplete defecation, and lower abdominal pain in advanced stage. (2) Intestinal stenosis symptoms, cancer invasion causes intestinal stenosis, deformation and thinning of stool at first, and intestinal obstruction in severe cases. (3) Symptoms of infection due to cancer breakage, with blood and mucus on the surface of stool, or even pus and blood stool. With the improvement of life quality, the incidence of colon and rectal cancer is increasing year by year. When you have the above symptoms and the common medication is not effective, you must go to hospital for further examination as early as possible for early detection and treatment.