Shar Pei- Loss of appetite and diarrhea

[Dawwns]

We have a 9 yr old Bearcoat Shar Pei. After vaccinations Dakota suddenly got diarrhea. Took him to vet and was given antibiotics. Diarrhea continued followed by loss of appetite. Took him to another vet who did an in depth blood work up and all came back good. The vet said he was stumped. Had chart faxed back to first vet and she continued antibiotics and gave steroids. The diarrhea then went to a mashed potato consistency and he did start to eat and even put on 2 LBS. After stepping down steroids we are back to original problem. Vet is doing steroids again with continued antibiots and something to coat the stomach. Still no one has any answers. She said biopsies sent to three labs will give you three different answers and ultrasound may not tell anything, but could be possible gastric cancer, again a guess. When I say diarrhea I don't mean he is going constantly, it's when he goes it is of a diarrhea consistency. We don't want to put him down for an I don't know answer. Since this is has gone on for a few weeks now couldn't his digestive tract and intestines be so irritated that it hasn't healed. We are just grasping for answers and anything we can do to save him. Actually this is my moms dog and now I have resorted to the internet to try and find something. He has always been a healthy dog, no problems.