Tracy,
I realize that you had had him combo tested at Katie's request and also that you wormed him and I took the paperwork with me to the vet and she saw it, but I am sure you know since you have been in rescue for so many years that it is a normal routine for a vet to retest a cat that is having problems with diarrhea etc. Tests can be wrong or show a false result so vets will retest to make absolutely sure. When Shay was having diarrhea and vomiting problems a while back the vet retested her even though she had already been tested and tested negative. It is just a precaution. I am sure I am not telling you anything you already don't know. The worming was a precaution too since his intestines were upset causing the diarrhea. I am sure with the meds and the prescription food that he is on for it he will be just fine. There is nothing for you to worry about, he is in good hands and hopefully soon he will be in Katie's arms. I can't wait for her to meet him. We are working on those details and I am sure Katie will let you know when they are finalized.
Melissa