Debbie...this may sound strange but I had a "Natural Cat" book decades ago and I remember reading that natural bran added to wet cat food works both ways. It can help stop the runs as well as help a constipated kitty. I've never tried it, mind you. That was back in the 80's when I made my own kitty food and added all kinds of vitamins to it.

...but then again, Tracey could be on the right track.