Well, I think he was constipated - this morning when I got up he seemed a bit better, but definitely needed a bath because -- well I'm sure you get the picture.
He seemed a lot better after the bath, I gave him some more Early Comfort. He didn't seem that interested in eating -- but then I think I discovered what caused his problem
Apparently, my dd knocked a sandwich out of the fridge. He must have tore through the baggy and ate the chicken & turkey sandwich with cheese & mayo

. (how she didn't notice

)
I found the baggy between his bed and the wall -- I'm thinking he ate it all and Roxy must have been outside when this happened because she is acting as normal as possible.
He's still a bit sluggish - but better than last night.
Thanks again for all the great advice -- hopefully we won't be in this situation again