Routine blood markers for bowel cancer are often useful to monitor patients for anemia and infections, among other things. It can also be used as the monitoring index of side effects after treatment. 1. Anemia: most of the patients with bowel cancer may have blood in stool, and prolonged blood in stool may easily lead to anemia. Observing the amount of hemoglobin in routine blood test can timely discover whether the patient with bowel cancer is anemic or not, so that corresponding symptomatic treatment can be given in time. 2. Infection: Bowel cancer patients may undergo surgery, radiotherapy, chemotherapy and other treatments, which lead to low immunity of the body and easily lead to various kinds of infections. Monitoring the value of leukocytes through routine blood test can tell whether the body is infected or not and evaluate the severity of infection, so as to give symptomatic treatments in time. 3. Side effect monitoring: detecting whether there is bone marrow suppression after treatment. It is suggested that patients with intestinal cancer should go to the hospital regularly to improve the relevant examination under the guidance of doctors, so as to clarify the changes of the condition and avoid delaying the condition.