Blood test for bowel cancer mainly looks at blood routine, liver and kidney function, tumor markers and so on. 1. Blood routine: mainly look at red blood cells, white blood cells, hemoglobin and other items. Among them, red blood cells and hemoglobin can clarify whether the patient is anemic or not, and initially analyze the patient’s physical condition. White blood cells are related to the inflammatory reaction of the body. 2. Liver and kidney function: mainly to see the patient’s liver and kidney function. During treatment, some chemotherapy drugs or targeted drugs need to be metabolized through the liver pathway and kidney pathway, which may cause liver and kidney function damage. Early conditioning treatment can also ensure the patient’s body function. 3. Tumor markers: mainly CEA (carcinoembryonic antigen), CA-199, CA-125 and so on. If the values of the above indicators are stable, it means that the patient’s treatment situation is relatively stable. If the value of the above indicators is stable, it means that the patient’s treatment is stable. If the above indicators are obviously elevated, it suggests that the patient may have recurrence or metastasis of the lesion. It is necessary to combine with other tests to clarify the patient’s current situation before treatment. It is recommended to consult the hospital and standardize the examination and treatment.