PET-CT should refer to PET-CT, bowel cancer can be detected by PET-CT. PET-CT is the integration of PET and CT in a single instrument to form a complete imaging system, which can be used as a method of detecting bowel cancer, and is of high value in the diagnosis of early-stage bowel cancer lesions, clinical staging, and the presence of metastasis. PET is an imaging device that can reflect the genetic, molecular, metabolic and functional status of the lesion, while CT is a physical examination of the human body using X-rays. The integration of these two technologies allows rapid scanning of the whole body, as well as obtaining anatomical and metabolic images. Bowel cancer is a cancer that occurs in the colon or rectum. The specific causes of bowel cancer are still unclear, and clinical symptoms include diarrhea, constipation, bloody stools, and mucus stools. It is recommended that when patients have symptoms such as bloody stools, they should go to the hospital in time for PET-CT and other tests to clarify the cause of the disease, and under the guidance of the doctor, treatment should be carried out.