I'm currently in the process of training my cat to use the toilet with the citikitty toilet training potty, www.citikitty.com
and so far Iâ€™m having no problems. My 2 cats are both just under 2 years and have both been litter trained.. I moved from a spacious apartment in the suburbs, to a small
city apartment with no room for a standard sized litter box in the bathroom. One of my cats was acting alittle aloof with my boyfriend for a few days, but no major stress for either kitty.
I've read that a cats natural inclination is to bury her/his stool in sand or dirt, so even if their toilet trained, if they see a litter box (or perhaps a potted plant) so if they were forced into a situation where the litter box was their only option I don't think it will be a problem.
As far as detecting medical issues go...they are young, indoor, cats, whom I take to the vet three times a year for checkups, and countless times because they "looked queasy", between my neuroses and the vets medical expertise, I think my babies will be fine.