Start by taking him outside immediately after you come back inside. Sounds weird, I know, but once you come inside, watch him like a hawk for a few minutes, then straight back outside, and hopefully he poops. Make sure to treat and praise and have a party for him.
It's going to be a bit difficult to keep him from pooping inside if you can't kennel him while you're gone. Do you have a small bathroom or area you can baby gate off? Will he tolerate that confinement?
It's going to be a bit difficult to keep him from pooping inside if you can't kennel him while you're gone. Do you have a small bathroom or area you can baby gate off? Will he tolerate that confinement?