Combination Feeding - any opinions on this?

[Lizzzombie]

Hi, I BF my LO (18 wks) at 6am and 6pm and the 3 feeds inbetween are FF - I am returning to work in a few weeks time and thats why I am putting him onto FF. Expressing caused probs as I have huge boobs, and it just caused mega engorgement. Anyway. He has been having a combination of BF and FF feeds for about 3 weeks now, and I've noticed he pukes much much more after a BF.
Has anyone else come across this?
I know this sounds daft, but could it be because my milk is 'stale' as it has sat in my boobs for 12 hours? As opposed to when I BF all my feeds?
(do I win the divvy question of the day for that?!)

Milk isnt stale, cant go stale.

Ok, but is there something which could be making him puke much more than usual after a BF compared to a FF?

I combination fed my first child, similar times to yourself the first feed of the day and the last feed. He also use to puke more at these times but my Health Visitor told me that it was probably due to him feeding faster in the morning (with it being the first feed of the day he would guzzle) the 6pm feed usually coincided with the onset of teatime cholic/ baby indigestion so it could be just a coincidence of the times these feeds are at rather than your breast milk.

Could you perhaps for a couple of days swap your BF and FF around and see if the sickness still occurs at the same times.

Thanks for the advice Louise, I will try that.