I recently got an orphaned kitty. I'm assuming she's around 4 1/2 to 5 weeks. She's playful and when I scartch behind her ears she purrs really loudly. But, My kitty well hasn't gone to the restroom. She's gone 1 but not 2. I'm scared her insides may rupture or something. I keep running to the restroom to check on her. And the other thing. Is food. She's eating about 5 TBSP. of food everyday. And seem to be fine. But when do I make the change to a regular food or even ground tuna or something. Anyone have advice?