14yr old sticking tongue out hiding constipated

I recently went on a two week vacation and left him with a friend, he hasn't been eating as much or drinking water at all. He isn't peeing as normal, his poop is small and round and sometimes runny. Recently he's been hiding instead of sleeping on the bed as normal, as of a few days he's had his tongue out all the time... Help me. He's my baby.

I'm new here but I found this site after researching this exact same problem

PLEASE CALL A VET, GOOGLE DEHYDRATION IN CATS, AND DO WHAT THE VET SAYS ASAP

the morning before my 16 yo cat died her breath smelled like ammonia for the first time EVER

HE most likely HAS TO HAVE WATER

Might need sub q to help bounce back. Since you were away for an extended period he missed you and probably depressed. Try a probiotic to get him back on track but he sounds like he needs fluid.

I think a trip to the vet today for sub-q fluids is needed.  Sub-q fluids usually perks them up really well.  If he's impacted he may also need an enema.  Unfortunately kitties don't adapt well to change so hopefully just the fluids and possibly enema will get him back right again.

Vet...NOW!  This is urgent and all of these behaviors are indicative of something terribly not right.