The best thing you can do is teach those 2 four year olds about real health and to not believe authority figures or professionals just because they say that they are correct. Teach them to play chess and to think for themselves. Tell them what really happened to the native american indians after their teacher tells them the glorified G rated version.
Tell your kids that they might be right about things that the president of the US is wrong about. Tell them to not drink the fluoride/chlorine/alum cocktail tap water and that mercury is bad. Give them whole foods loaded with enzymes and real vitamins and minerals, and salads and bananas. Show them the truth. Show them pictures of what a smoker's lung looks like. Show them before and after meth-head pictures. Watch an hour of tv with your kids and tell them each lie that you see on tv - including commercials.
This gall bladder experience could be the spark that prevents the same type of thing happening to your kids. Tell them what happened and give them the power to think for themselves, and to watch out for people who have ulterior motives - even professionals, authority figures, neighbors, and politicians.
sorry rambling but this type of thing that happened to you pisses me off......