Metronidazole is commonly known as Flagyl and it is often given for
diahrea. It is given if giardia is present and often it is given when
the diahrea persists after other anti-diahrea meds have been given. I
have used it in the past for kittys with different conditions.
Slippery elm can also be given for diahrea or constipation. There are
posts that give the amount to be given.
Hope this helps.