Ok, "outside" in the case of our house is an extension of the house that's sheltered and comfortable, but has access to the rear yard. Not going to feel bad for not having a dog inside that is going to go to the toilet everywhere, especially with young children. Also, he gets walked two x daily so not sure how he has the raw end of any deal. As I have said, never had an issue before with giving dogs marrow bones at about this age.
The dietary change was on instruction from the vet. I would prefer to make his food myself but the vet told me to use a high quality commercial feed until twelve months. There is no breeder instructions, and I can't get hold of the person we got him from. He is not dehydrated, he gets plenty of water which is constantly checked. He is also eating fine. As for being depressed, probably too strong of a word...what I meant was he is sooking basically because he is used to being inside at night on the couch.
I was really just looking for, as I mentioned clearly in my post, whether sensitive stomachs was a breed specific problem which anyone else had encountered. Other than the diarrhea he seems fine. Just got him up a little while ago for his morning walk and he is energetic. Just waiting now to check his bowel movement when he has it to see if its hardened up a little.