Patients with bowel cancer may have changes in their blood counts such as reduced red blood cell counts and lowered hemoglobin. However, they do not occur in all patients. Therefore, the presence or absence of abnormalities in the blood count should never be used as a basis for determining whether or not a person has bowel cancer. Patients with bowel cancer may experience persistent gastrointestinal bleeding, which can lead to chronic anemia, which is reflected in a reduced red blood cell count and decreased hemoglobin concentration in the blood count. However, not all bowel cancer patients will have chronic anemia. Anemia can be used as a diagnostic basis for bowel cancer, but not as a definitive diagnosis. In addition to routine blood tests, patients suspected of having bowel cancer can also improve some other tests, such as tumor markers, abdominal CT, colonoscopy, etc. Among them, colonoscopy combined with histological biopsy can not only clearly diagnose whether they are suffering from bowel cancer or not, but also further clarify its pathological type, which can provide the basis for the next step of treatment. In addition, if the patient is receiving chemotherapy for bowel cancer, due to bone marrow suppression, there may be abnormalities in white blood cells, platelets and other indicators. It is recommended that the patient should go to the hospital in time to complete the above examinations and lab tests to make a clear diagnosis.