You don't need to bring her to vet to have her checked for mites/parasites. Mite you can check for yourself, and parasites you just need a stool sample. Just like the IBD though, it is very unlikely that she would have mites/parasites if you have had her for 3 yrs. and not introduced her to any other animals, or handled any other animals and then her right after. Just out of curiosity, did you notice the staring into space and head shaking and the go read about IBD because of it, or did you read about IBD and the notice the head shaking and staring. If the later, it may just be a case of hypochondria.
They call the fingers, but I ain't never seen 'em fing.....oh, there they go