I had to switch dry foods and I wasn't able to ween them onto the new stuff. I was going with Avoderm but ran out, and in a pinch had to put them on Merrick. Both are grain-less. Only the male got sick, my female doesn't seem to have any problems, however I don't think she ate as much. I'm going to do what I can to get some Avoderm tomorrow; at what point should I be worried?
If its not cleared up in another day or two get the kitten to the vet. You do know that Bengals are not supposed to be on an all dry food diet! They have sensitive stomachs and need a high protein diet. Its best to feed more canned foods (high quality) and raw rather then the dry.
Kitten are highly susceptible to intestinal parasites and the most common symptom is diarrhea. I would suggest getting your kitten tested before you assume its food even if you just had it done .