I can totally sypmathise. My DS1 was like this as a baby. He was a shocking feeder and NEVER took more than about 80mls until he was well over 6 months. It was a never ending battle. I even ended up taking him to a Paed who said that he was happy and healthy and to just go with it. It was totally frustating thouugh.

I also now have an almost 7 week old little boy and he is a much better feeder than DS1 was, he averages around 120-130ml a bottle.