My parents' dog has pacreatitis. She seems to have problems rather like I had with my gall bladder--bile vomiting, diarrhea, loss of appetite. Our vet prescribed her some pills, and they give them to her when she's acting sick and they seem to fix her right up in a day or two. It's hard to tell if she's in pain or not, but she certainly lays around the house sleeping most of the time when she's sick, and she moves very slowly, as though she is in pain.
If a dog can get it, I certainly don't see why a human can't have it too.