No idea at all what the problem is? When did you last see him eat, drink, poop and pee? Notice anything unusual? Does he feel cold? Or hot?
Is uncomfortable when he's hopping? Could he have hurt his back?
Is he pressing his tummy flat? That could be a sign of gas.
Definitely keep him warm, calm and hydrated until you get more info.
If you're sure he's not injured, I'd treat for gas, it's often the case and it won't hurt him. He'll need simethicone gas meds, so if you have any GasX or anything, try that every hour for three hours. I give my little guys a quarter of a tab of berry flavored 40 or 60 mtg suspension, but you can't really overdose on the stuff (although too little won't do any good), it's not absorbed by the tissues, it just breaks up gas bubbles.
You can also use baby gas meds, I give my guys a full CC or more every hour for three hours. If it is gas, he'll pop out of it within 12 hours or so. If it goes longer than that, it still could be gas, but something else (like a blockage or GI tract slow down) is causing it so more action will be required.
Also go for gentle tummy massages, again to break up gas bubbles, or even sit him on top of a vibrating dryer or use a vibrating toothbrush (or um.. something) on his tummy.
If you think he may have not been pooping and is having a bout of stasis, massage in the direction of the anus to try and help stimulate the tract.
You can also keep trying to temp him with wet treats like water soaked parsley. If I wave it in their faces long enough, they get mad and grab it. Although don't worry about force feeding him unless he's missed meals and isn't pooping.
Also if it's gas or stasis, exercise is good (although stress free exercise), but make sure that it's not a skeletal issue or something first.
Let us know how he is!
sas :imsick: