Kitten with stinky poop.

We have had Pyewacket a week today and she has been perfect about her litter box. The day I brought her home I started free feeding her dry blue buffalo kitten food and she also gets a quarter can of blue buffalo wet kitten food. I also use a wood pellet in her litter box instead of traditional cat litter. I have a house rabbit and I won't risk keeping clay kitty litter around because bunny is free range and if she got into it she could die.

So its been a week and Pyewacket still has very smelly poop. I will say its not as bad as the first two days but its still pretty stinky. Right now her litter box is in our bedroom as she is mostly confined to the bedroom because she is so small and the bunny is still being introduced to her in stages.

She has been to the vet and has had a clean bill of health except for a slight eye issue which has cleared and she had some fleas which are now all gone (thank goodness). But I am still wondering about smelly kitty.

Any advice?

What kind of food was Pyewacket getting before?  The change in diet could cause him some upset.  

Also, when we first brought home our kitten Rico, we called him Stinky Ricky because his poo was runny and awful-smelling. We couldn't believe anything so foul smelling came out of such a small, cute cat!      He, too, was healthy--it turns out he was just very nervous and scared.  After a couple of months he was used to his new home and food, and all was fine after that.