Jasper spent a good part of the afternoon at the vet, getting blood drawn and x-rays taken. Preliminary bloodwork looks ok, the x-rays were a little inconclusive as to whether there was any intestinal blockage or not. We don't THINK there is, but the next 24 hours will be key. If he has any more vomiting or diarrhea (especially vomiting) he'll go back to the vet for more x-rays and tests.
He seems to be feeling ok right now. He was hungry tonight. I cooked him chicken and rice (bland diet), and fed him 3 times over the evening, about 1/3 cup at a time, to keep from stressing his tum.
So far, so good. I've got to get a poop sample the next time he poops, but picking up poop holds absolutely no terrors for me.
Keep your fingers crossed for us.