Fish stuck inside hole in rock!

I have a bunch of Texas holey rock in my tank - the Mbunas love it - a few
months ago I had a real nice loach ("variegated", or something like that) -
he was about 2 1/2 - 3 inches long - good and healthy, always active, poking
into the crevices and such - and then I just never saw him any more - I'm
used to fish disappearing in this tank - I figured he maybe looked sick or
something to the other fish, they turned on him, and in the morning he just
wasn't there any more. I guess it's been at least a couple of months since
I've seen him. So I'm looking in the tank during dinner tonight and there
he is, with his head poking out of a hole in the holey rock - I go over to
investigate, and he ducks back in, but with a flashlight, I can see back
into the hole and there he is - a while after I back away, and he'll poke
out a bit - he gets maybe an inch or so out and that's as far as I've seen
him come out - I'm convinced that, somehow, he's stuck in there and can't
get out - I work at home all day so I pass by and look at this tank A LOT,
and I absolutely have not seen this guy swimming around for the past few
months - until tonight - any suggestions on how to coax him out, or force
him out? Thanks!