Your child’s primary concern is passing of abnormal stools . Does your child also have fever ? Blood in stools ?does your child have any sign of dehydration? ( sunken eyes / dry mouth / lethargy/ irritability? If no , then there are no danger signs at present . Your child might have acquired a viral infection which caused the diarrhea and further development transient intolerance to lactose due to the viral infection. Signs of lactose intolerance are prolonged diarrhea with passing foul smelling, explosive, gassy, bulky stools . I suggest that you start your baby on lactose free formula feeding like Zerolac / Isomil for a few days and reduce the frequency of breast feeding . If your childs symptoms resolve , then gradually reintroduce breast milk and reduce formula feeding . Stool routine and microsopy might be required to be done to rule out parasitic infection.