Took Rem back to the vet's today for a follow-up. He's been feeling & acting fine. His weight was down somewhere between 2.5 and 5 lbs from 2 weeks ago (depending on which scale they used--smaller amount was on the same scale he was weighed on then), though, which is a little odd, as he's been less active but eating the same amount of stuff--I think. Just occurs to me, maybe because I'm not doing as much with him, he's not getting as much Rollover? But, still, that's a LOT of weight in a very short period of time. He didn't have that much diarrhea or for all that long, and that was 2 weeks ago. So I'm teaching him to stand on the bathroom scales & am upping his food 10% for a couple of weeks to see what happens.
His blood test came back with everything back in the normal range except one liver test, which is slightly more moderately elevated than before. But the corresponding double-check test is completely normal. I dunno.