Could you tell me what are leads to of bloody bowel movements in newborn babies?

Common things...: Many things can cause this including anal fissures, an allergy, or something more complicated. If your baby has a bloody bowel movement, this is definitely a reason to make an appointment with the pediatrician. Bring in the bloody diaper as well. Take note of how baby is eating, acting and if there is a fever (best to not check this rectally since we aren't sure where the blood is coming from).