Cat toilet training problem!?

I have been training my cats to use the human toilet using the citikitty training system. (here) http://www.citikitty.com/
Everything has been going well up to now, i have done everything right (gone slowly, removing only 1/2 a ring at a time, cleaning it several times a day, etc). They have been very good so far and havent had any accidents until now. I am at ring 2, and i have been there for at least a week and she have used it fine. Last night, my cat had an accident and pooped on the carpet and peed there as well. She had diarreaa, so maybe she wasnt feeling well so does that have anything to do with it?
I am going on a trip in a week and i dont know what i can do!!!! how do i convince her to use the toilet? what should i do?

a BIG problem about toilet training cat, or is it?

what if i have finally trained my cat to use the toilet and i have to go to another house during summer and the holidays? what do i do with my cat? i would prefer bringing her rather than leave her, cause no one could take care of her. what should i do?
what i meant was, i will bring her to another home, and let here use a litter box there (i cant make her stay inside the house, cause my mo goes crazy, haha). would she still remember to use the toilet back in my previous house?