How do you train an adopted dog to poop outdoors?

Consistency. Feed at regular times, then take the dog outside about 1/2 HR later. Do not allow dog unlimited access to water in the evening, Let the dog have a little drink after it's last walk , then put food and water bowls up , and make sure the toilet is not an available water source. If a dog leaves you a little " surprise " while your out, don't scold it. It will not know why it's in trouble. If you see the dog looking for a spot to go, grab the leash and get outside fast. Praise doggie effusively when it goes while outside, and give a small treat. If you train a dog on newspaper, it will look for newspaper outside unless s/he gets the scent of another dog.