When a child has a bowel movement, sometimes dry stools or diarrhea are not normal, and sometimes there is blood in the stool. When a child has blood in the stool it often startles the parents. In the case of particularly small babies, small newborn babies, it is likely that milk protein allergy has occurred and allergic colorectitis has occurred, which is very common. Blood can be seen in the stool of a small baby. The child can have other manifestations of poor milk consumption and abdominal discomfort, which can also affect the child’s growth and development over time. Avoiding the diet that causes the child’s allergies is the ultimate and only solution. Of course at this age there are also many important and serious diseases that need to be differentiated, such as necrotizing small bowel colitis, intussusception, neonatal bleeding disorder, etc., all of which may be manifested as blood in the stool. Of course, there is also the more common constipated child with anal fissures, thick and dry stools with blood on the surface. There are also babies who have intestinal infections and have broken intestinal mucosa, and their stools will also be bloody inside. Therefore, it can be seen that the causes of blood in the stool of children at different ages can actually be very different. When a child is found to have blood in the stool, it is important to observe the mental state and the shape of the stool, and then seek medical attention to provide the doctor with complete information to help with diagnosis and differential diagnosis.