I usually dont prescribe ceftriaxone for gut infections, because the drug itself causes antibiotic associated diarrhea. But if the doctors found the organism to be sensitive to ceftraixone, U need to follow their advice. If, even after the ceftriaxone course, ur baby continues to have diarrhea, he needs to be evaluated for lactose intolerance and other types of non infectious diarrhea. Let us wait and see... Another thing, weaning from breast milk to other foods itself will cause prolonged diarrhea. Till then see to that ur baby is properly hydrated with oral fluids and a nutritious diet except for milk. U can give curd. Rice or barley porridge with a little salt and little more sugar is very useful in arresting the diarrhea and replacing the nutrients. Since ur baby is in weaning period, U have to introduce these foods gradually.