Question
The baby started experiencing diarrhea four days ago after switching to a new formula without a gradual transition. The diarrhea stopped for a day when the baby didn’t consume any formula, and the stool returned to normal. However, after switching back to the old formula yesterday, the baby still has a slight case of diarrhea, but it’s not very loose. The old formula has been used for over a year; why is the baby still having diarrhea? The baby is currently taking probiotics; how should the formula be fed now?