Took a bit of effort for me to find a site that had a pronunciation guide as well as a definition for Giardia. Here 'tis: http://www.thefreedictionary.com/giardia (jee-AR-dee-ah)

The powdered fiber in the food isn't doing squat (if you'll pardon the expression) for The Little Prince so far. I'll give it a chance till Monday, mainly because I have a daytime gig tomorrow and the vet clinic is closed Sundays, and then if there's still no change I'll call the vet again and suggest the possibility of Giardia. If that's what the problem is, I'll have to treat both cats because they have been sharing space (and litter boxes) for a couple of weeks now. The Drama Queen (6-year-old Madison) shows no signs of loosening stools, fortunately, but that doesn't mean she couldn't have picked up the disease or pick it up in future before it's diagnosed. Oy! Thanks again for the info, Becky.