Jono,

Diarrhea can be caused by many things. Parasites such as hookworms and
roundworms will cause diarrhea, sometimes bloody diarrhea (hookworms).
Coccidia and Giardia are protozoa that live in the intestinal tract and will
also cause chronic bloody stools if they proliferate or if there are times
of stress. Most of the time, medications will clear both conditions.
Irritation to the bowel can cause bloody stools and again, medications will
clear this up. If your veterinarian has not performed a fecal exam, that's
the first thing that should be done. This will rule out intestinal parasites
such as hookworms and roundworms. Giardia can be difficult to find on a
fecal so if the fecal is negative and your cat has not been treated for
giardia, I would advise treating anyway. The medication won't hurt your cat
if she doesn't have Giardia, but it will certainly make her feel better if
she does. Kidney disease is one cause of diarrhea in cats but 9 weeks is too
young for kidney failure. Blood tests should be able to rule in or out this
problem.

I would have your vet perform a complete physical, fecal exam included,
treat for intestinal parasites if any found, and treat for giardia if this
has not been done. If the diarrhea persists, further diagnostics should be
done to determine the underlying cause (bloodworm, intestinal biopsies,
etc.) Nonetheless, all the symptoms that you mentioned indicate that worms
are present. Worms are very common, and roundworms can be caught from other
cats, and even be ingested through mothers' milk. Symptoms in kittens
include a poor coat, diarrhea and a swollen stomach. Tapeworms can be begin
life in cat fleas which your kitten could have eaten. I would start with the
simple things first and go from there. I suggest you find another vet that
will see your cat sooner than the one you are scheduled to see. I hope this
helps.