BLUE TONGUE SKINKS

Hello all!
My Blue Tongue, Blue, was NOT eating well at ALL a while back (Hes a baby). Some of you guys recommended a good high protein dog food. I've been feeding him that out of the cage and every day, little by little, his appetite has improved!
But I have only been feeding him dog food, and his poop is... not good. Its like diarrhea (From what I've seen of it.) Its brown and just kinda soupy? Like I said, he just eats dog food at the moment. Is he sick? What should I do?

How long have you had him? Did he previously have a different diet? Sudden changes in diet can cause diarrhea for a while. You may also want to have a fecal check done.

I've had him for about a month and a half - two months. Previously he was being fed crickets, fruits, and veggies. For the first little bit I was feeding him fruits and veggies but he wouldn't eat it, so I went to dog food

Well, if you haven't been feeding him dog food for a very long time, his digestive system may still be adjusting to the new diet. Also, adding veggies to the diet will give him roughage that helps his digestive system. If the diarrhea continues, you should probably have a fecal done.