Persistent diarrhea for years

[Amy]

Our to be 3 year old doodle (in May!) has had chronic on/off diarrhea and sometimes vomiting since he was a few months old. We have tried switching foods to no avail. Multiple times he would go in for a stool sample and/or lab work. Over the time, the only thing that would seem low or off was his B12. He was on B12 shots weekly and then monthly, again didn't seem to make a big a difference. Our vet suggest switching to Purina EN Gastroenteric, he has been on it for 6 months and again, no change to his diarrhea frequency.

They now want to do another stool sample to see if anything would show up as well as suggested doing a scope and biopsy on his stomach. 

Another option they gave us is to try a hypoallergic dog that is very costly, which may be worth it if he doesn't have issues in the future, but is about $70 for a 16 pound bag. 

My question is has anyone else dealt with this and gotten any answers or any advise on what to do?

[Amy]

I really appreciate your insight. We were very surprised when they didn't automatically refer us for the scope since that was what they had said they would happen when we spoke with them on the phone prior to the appointment. We knew the scope would be expensive but thought if we could get a definitive answer it would be worth it, hopefully they are just trying to see if they could save us money and find answers without spending the money at the specialist.

[Karen, Jasper and Jackdoodle]

It's been my experience that it never saves you money to put off doing the definitive diagnostic testing, whether it's a scope to diagnosis IBD or skin testing to diagnose allergies. It would be different if any of the tests a GP vet can run would actually give an answer, but that never seems to be the case. And with most of these immune-mediated diseases, the big expensive tests are the only way to accurately diagnose them, so you end up having to do it anyway.