Oh Chris, I'm so sorry to hear Bobby has health problems, he is such a sweet boy and I always love to hear what he's up to, and see pictures/videos of him.

It sounds like you have had him checked for all sorts of things, but has he been x-rayed? I hope there are foods that will agree with his tummy.

Sending lots of good thoughts and we're keeping all paws and fingers crossed for Bobby.

(((hugs))) to you.