I would add another solid feed late in the afternoon and change his night boob feed to a bottle one. Between the extra solids and the formula he might just sleep through again because he is fuller.

I have heard of babies changing their sleeping patterns at about 6 months. I'm hoping my daughter doesn't do it, i agree with what the other mum's have said. Try to give your son the formula before bed it may help him sleep better because it fills them up more.

Hope this helps

is this a very recent change?  My 10 month old twins do this when they are going through a growth spurt and usually it only lasts about 4 days and then they're back to their old schedule.

Perhaps instead of giving him the breast just before bed, you could give him formula so he doesnt wake up as often. Babies can often change their sleeping routines - you just need to remember to not let them sleep all day - as this can interfere with their night time sleeping routine also.

Good luck and hope he settles better for you soon.