I was going to say I put breast milk in the bottle rub some of the milk in the bottle nipple so he smells and tastes it. And if ur changing totally to formula slowly mix half and half ur milk with formula then little less if yr milk and more formula like every few days. Good luck. ;)
We had problems with my son taking a bottle until dr suggested using Playtex bottles and enfamil newborn (apparently closest tasting to breast milk).
After that no problems at all.
Try someone else offering the bottle to him, because you smell like breast milk. Also taste the milk if you offering formula, because breast milk is sweet, a lot of formulas taste horrid! Mostly I found it was just perseverance.
If you dr has no problems with his poo-ing patern the don't force a change. It could cause problems where once there wasn't any.
Good luck!