With a pup with so many stomache/bowel problems I would personally look into raw feeding then you will know what he's eating,if you are going to feed the suggested kibble then you will have to keep him on it for at least 8 weeks to realise wether it's suiting him,I wouldn't feed any treats,dairy including eggs,rice ,grains ,I would give a good probiotic to put flora back into his gut,don't over feed as that too will cause diarrhea and vomiting,you could feed tripe which is full of probiotics also and will put wieght on him,let him rest after each feed ,it sounds like he's been through the mill and a pup so young will be very stressed which will also contribute to upset stomache,once you find a feed that suits dont be tempted to change the feed,try and not be persuaded into giving more meds from the vet as they can do more harm than good,personally I'd change vets ,do your research on your pups troubles you may be surprised what you learn ,it's very hard sometimes to find a feed that suits your dog but any feed that vets recommend is rubbish and it's only the vets are the winners ,I hope you sort these problems out ,karen