New Formula

I found a just born kitten on my lawn 20 days ago, she is eatting really well, and is growing fast, my problem is that, the vet in my small town ran out of kitten formula (nurturall), I had to buy a different formula (mammalac) from a different vet, now she has very loose bowel movements about once a day, I have tried adding more water to her formula, but it doesn't seem to help.

The loose bowels after changing formulas or food is quite normal since the cat/kitten is getting used to the formula. It would be better if you could get your hands onto some goats milk if possible - less troubling to her little belly. Keep her on her current formula if no others are available, she'll get used to it.