I just recently took home an 8 week old kitten from our local pet store. On the first day she had a solid stool but for the week that we have had her it's been nothing but diarrhea, once to the point of being complete liquid. Right now we are feeding her friskies kitten formula dry food, different from what was given at the store. She has been de-wormed once and though we've searched her stool just in case, it appears to be worm free. I called a vet upon seeing blood in her stool, and was told that it was probably a combination of food + stress of adjusting. However, it has been a week and the problem persists even though we have not made any further adjustments to her diet. Just how long does it take for a kitten her age to adapt? Is it too late to call the pet store and switch back to what she was originally fed, or would I only be doing further damage? She eats and drinks as per normal and is energetic, but I'm concerned for her health as she looks a bit malnourished.