My ds2 did this when I went back to work. And we discovered we were using a fast flow nipple. So he was able to basically do nothing a get milk. And then when he went to bf it was hard work. So we switched to a slow flow nipple and he never fussed again. So check your nipple flow on the bottle.
Abby-mama to two beautiful boys (12/09 and 3/12), and wife to my fabulous DH