I am taking care of a chondro for my fiance while he's away.  I am familiar with how the animal is cared for as I have been caring for him for quite sometime now.  The animal usually always eats a large mouse once a week (live, what he's used to).  The pet store did not have any large mice when I went this last week, but had a small rat, my only other option was taking alot of pinkies.  I took the smallest of the rats they had and just assumed that if it was too big for him he wouldn't eat it.  He did downed the and I thought all was ok.  I looked to see how much of a bump it made in his belly and it didn't appear to be very noticeable (the way he was laying didn't help me evaluate that too well, though), so I thought ok no worries. (I had already been thinking that he might be outgrowing the large mouse anyway.)   I went to bed and woke up to find him laying under the papertowels in the bottom of his cage.  I thought he was being silly as I've seen him on more than one occassion root under them but when I came home from work he was still there.  I touched him a bit to evaluate responsiveness and his head came up quick looked at me and started to move in a territorial way toward me.  At that point I closed the cage and let him be.  This morning I woke up to find him under the papertowels still, this time he needed a little rousing to get a response out of him (could be he was asleep and needed a second to gather his faculties), I misted him down extra this morning to where it puddled all around where he was laying.  I moved his water bowl closer to him to make it easier for him to drink if he's not feeling well, and removed half of the paper towels to keep them from absorbing the extra water where he was laying.  

The animal is about 3 1/2 yrs old, with no known problems, he poops regularly, usually runs his cage at night, drinks from his water bowl, and has never refused a meal.  The temps are kept somewhere between 85-89 during the day, usually the night drops to about 75-80, but lately outside night temps are in the 50-60's and I have no heat in my house so the lamps have stayed on (I live where it's warm about 99% of the year). I made the mistake of not turning them on one night not knowing we had a cold front come through in the night,  the cage temp dropped to 65 when i woke up the next morning.

Should I take him to a vet?  I'm sorry this is so long, but I wanted to include as much detail as I could.  Any advise would be helpful.  I've read where some people have used water as a substrate to super saturate the animal until it's pooped.  Is this recommended?  Thanks!

By the way.  I don't have a way to upload photos right now, I will try to work on that issue, but in the meantime this is the situation.