Automatic Litterbox Central

Ok, here is our story. Got the cat 2 mths ago, had solid stool for 2 days. Decided I didn't like the cheap litter that the prev. owner was using so switched to the Fresh Step Crystals. Gave the cat a choice and he seemed to like the crystals. Then we started having a severe diarrhea problem. Been dewormed for every one cell on up parasite and still we have sloppy droppings.
Well, I got this idea that I would put out the old litter to use it up and bam........haven't had much of a diarrhea problem.
We have been to two different vets and got a referral to see a specialist at University of Michigan vet hospital because they are clueless to why we are having so much problem.
He has also been on steroids and antibiotics.

Just wondering if anyone else has had this problem......

I don't know if this will help, but I'll share our similar story anyway. Lily had a lot of parasites when we found her. We found her in a local park near a bayou and who knows what kind of water and food she got into. Anyhow, she had runny poo even after three visits to the vets for the parasites. The vet finally prescribed barium and antibiotics. We had to give her the barium shortly after the antibiotics (or the other way around, can't remember). The solution was that her stomach lining had been damaged by the parasites, so it was infected on the inside. The antibiotics would help the infection and the barium would help coat the stomach so it wouldn't get more sores. I know this sounds really gross, but I thought I'd pass it along in case it is helpful.

Carrie