Poofy is doing a bit better these days. The antibiotic cocktail that we've been injecting into and feeding to him seems to be doing the trick. Our optimism that he would make a full recovery was tempered by a visit to the vet who told us that full recovery via antibiotics does happen but is pretty rare.
Nevertheless, she said that since Poofy is responding very well to the anitbiotics, we can keep them going for another 3 weeks or so and just make sure he eats a lot to make sure his stomach bacterium stay healthy.
Anyway, let's hope that the antibiotics do their thing and get Poofy back into a healthy state sans expensive and risky surgery.