Hello Mamaof3Bees:
Welcome to the forum.
I was wondering if you have ever tried Slippery Elm Bark for any of the bowel issues? I've used it in the past for diarhea and had good success with it. It might be something worth looking into.
I'm enclosing a web site for Little Big Cats that will describe the application and how to prepare.
What I found was buying bulk Slippery Elm seemed to make a better product than using capsules and do taste it before giving it to the cat to make sure that it meets Little Big Cat specs.
Couple of other things that I have some questions about. What type of food is the cat on? Has she been on antibiotics before for any reason and when was the last time it had vaccinations? In the past I've had problems with my cats with over prescriptions of antibiotics along with the vaccinations. Is the cat strictly an indoor cat, or does it go outdoors as well?
As Hazelrunpack mentioned - cats and antibiotics don't mix well due to their digestive systems - it's extremely high in healthy bacteria for digestion and antibiotics aren't selective. If it's bacteria, it kills it. If it's in the stomach, it can cause irritable bowel problems big time.
The month long prescription for antibiotics without having confirmed lab tests, diagnosis indicating that they are necessary, just seems to be a bit much, especially for such a small cat. The side effects are the major problem, according to my pharmacist.
http://www.littlebigcat.com/health/slippery-elm/