My favourite girl, a self black about 1.5 yrs old has tummy trouble

and I have no idea as to the cause and whether it is infectious to other mice or humans.
I have noticed it happening on and off for several weeks now but it has been nothing much and it certainly hasn't seemed to come to anything but now Inka has had the problem for several days and so before I go the the Vet I wondered if you guys had any ideas or advice?
Problem; It seems sporadic, I had just noticed Inka (and another mouse at a later date) passing formed but very soft droppings, their first droppings were fine but then followed by very soft droppings full of mucous.
Now Inka is passing mostly mucous and lots of it (yuk!) with some very soft but formed dropping in it, so I don't really know if it is true Diarrhea or whether she has another kind of gut infection? She does not seem unwell apart from being sneezy which she has been since I had her.( she has had repeated Baytrill treatment a while back from the Vet but to no avail-she just sneezes :roll: )
She is caged with 4 other does, only one of them showed any similar symptoms and only for a short time.
I feed 75% mixed grain base with 25% commercial mouse and gerbil mix , they have hay daily and twice a week they have a few bits of kibble. They have Rice krispies as hand treats.
I did wonder if maybe something in the feed was upsetting Inka so I have first removed the mouse mix, then changed the Hay type,now I have removed the grain mix also and just put them on a commercial hamster mix that a friend gave me to see what happens(it doesn't look very well balanced to me-even for the hamsters it intended for :shock: )
So please guys- any ideas would be great. As I say she will be taken to the Vet as it now seems to be becoming a definite problem but it would be good to know if anyone has heard of this before.
