Misty, my daughter 2.5wcf has been taking a probiotic daily since she was almost 18 months (so just over a year). If she goes on an anti then we double her dose. It really helps her digestion and I notice a bad change in her stools within days if I take her off of them - never really knew how much it did for her until I ran out and kept forgot to buy more for over a week.
HTH,
Kelli - mom of Sydney 2.5wcf