If you get a baby dosing syringe at the pharmacist, you can give the kitten straight CS rather than put it in the water. I change my pets water daily too. There is always bits of food and pet hair in it. I can't imagine that when the water gets like that it is very palatable, so I dump it and fill the bowls with fresh.
If your kitten is not eating, you can pick up some kitten formula and feed her that with the dosing syringe.
Plain, unflavored psyllium is good for loose stools too. A little will go a long way, too. If you use psyllium, you'll see what I mean. It thickens up very fast, use too much and it becomes quite gummy.