2 weeks after having gastro my 1yr old is still very upset in the belly , farts , pains , constipated .... How can I help him ?
You need to be more specific. Gastro what? Gastro just indicates stomach or digestive system. Either way I would strongly suggest calling the child's physician.
I think you need to talk to the pediatrician who attended to your child in the first place and have the problems attended to. Some of these symptoms may be a result of side effects from the procedure, which will also be addressed by the doctor.
Take him back to the doctor for follow up.
Your pediatrician will be able to help you figure of the reason for this and help you figure out how to get rid of the problem or help you. Take your child to the doctor.