No problem
Your baby won't have to be put under for an x-ray or ultrasound. It's really easy, and it won't hurt him in any way. If there are stones, they'll probably just put him on special food to dissolve the stones unless he has a large stone that will not dissolve. If that's the case, then he will have to have surgery to have that stone removed. Try not to worry yourself too much until you find out more. Keep us updated, and if you have any other questions, please ask.