He’s not moving from his litter box, or his cage? Has he pooped since the vet visit? Sometimes stress can cause gas ,or result in stasis, so if he hasn’t pooped in 6-12 hours he will need medical attention and have to go to the vet as it is serious.
For bonding, you’re right that patience is key. Some buns bond quickly, while others may take weeks or months. It took about 3-5 months for Luna to be comfortable around me, then by 8 months she fully trusted me. If you have only had him for a week it is normal for him to want to stay in/close to his cage because he feels safe there.
Tips:
– If his cage is in a room with a door, try closing the door to make the room look smaller so that he feels more secure in coming out of his cage.
– Most buns like being pet but do not like being picked up. If he doesn’t like being picked up, then don’t pick him up because the more you pick him up the more he will be afraid thinking that anytime you come near him he will get picked up.
– Sit/lay next to him as often as you can while he is in his cage and either talk to him or sit there while reading a book or something.
– Offer him some pellets from you hand.
– Hang in there! It’s worth it
.