When infants experience lactose intolerance, there is a possibility of bloody stools. With lactose intolerance, infants will exhibit symptoms such as an increased frequency of bowel movements, diarrhea, and bloating. If the frequency of bowel movements is particularly high, for instance more than ten times, or even more, especially over a prolonged period, the gastrointestinal function of the infant is not very perfect. An increase in bowel movements can exacerbate damage to the gastrointestinal mucosa, potentially leading to bloody stools. Additionally, when the frequency of bowel movements is very high, it could lead to damage to the perianal skin, which might also result in bloody stools. Or, when an infant has lactose intolerance, if they are also suffering from other viral or bacterial infections in the gastrointestinal tract, the likelihood of bloody stools may increase. Therefore, if we consider that an infant has lactose intolerance, it is crucial to promptly add lactase for treatment and to switch to a different formula for oral administration.