No dairy for 6 days after mucous/blood in 3 month old's stools. had sauce with dairy at lunch then by 6:00 pm mucous/spot of blood. reaction so soon?

Formula or breast: American Academy of Pediatrics recommends exclusive breastfeeding for the first six months of life, if baby is formula feeding, then you can start adding foods between four to six months of life, but even then only low risk for allergy foods like veggies. I would not give the baby any dairy products for now and check with your physician at the six month check up on how to proceed adding foods