D.M.
Hi,
I had the same issue. It took my baby two weeks of trying and not eating during the day at daycare but, she finally went back to the bottle. We tried every bottle and everyone trying. There are a lot of things we tried and you can try. Try facing your baby out, bouncing, a quiet room, other people etc. Finally, she ended up taking the bottle from me, facing out, bouncing. She wouldn't take it with breastmilk either. I had to get her to take it using formula. Now she will take either.
It was too hard for me to do on my own so, I had daycare to help. I'm not sure if that is an option or if there is someone that can try it everytime.
Good luck - he'll end up taking it if it is the only option. He won't let himself starve, you just may have a little screaming.
D.