Hi try not to be too despOndent, it's possibly a bit over cautious on the vets part keeping him in but to be fair she most likely wants to cover herself if not confident, could the wet chin have been from drinking from a bowl?
Usually the course of action is to work out when they last ate & drank & listen to the gut apparently there are 4 areas to listen to, they usually do a physical examination of the tummy area gently feeling it & assess the condition a bit more after teeth, eyes, ears, temperature has been checked, if they are pretty confident it's early stasis then they will inject metaclopromide the gut stimulant, metacam for pain & anti inflammatory & if necessary & ideally subcut fluids then you go home & do your best to let them rest, move around keep warm & tempt to eat if it doesn't work really they should check with X-ray IMO foe blockages & give iv fluids, that course of treatment worked for my doe but, I did insist on her coming home rather than staying overnight & I sous always emerging to do that just to keep stress to a minimum, I would have taken her back the following morning if she hadn't perked up. Fingers crossed your little guy will be alright & home again tomorrow, you need to keep a close eye on them for some time after as it can reoccur due to the upset in bacteria so stick to feeding little & often wet herbs like dill, flat leaf parsley & carrot tops, spring greens avoid 'gassy' veg like broccoli cabbage if poss & lots of high fibre like dandelions or plantain would be good thehayexperts do them dried I'd that helps best of luck hope he's home tomorrow & back to normality x