My DD is 5 1/2 months old. I've been block feeding, though I didn't know this is what it was called until recently. DD never showed an interest in the other breast, so after a while, I stopped offering. I have had a problem w/ OS from the get-go. DD was gassy, had green watery stools, gulping/choking, etc. I thought most of these things were behind us, as she still has watery stools, but they are no longer green, she only chokes occasionally and usually first thing in the morning when I'm really full, and she doesn't seem to be gassy all that often now. But, over the last month or so, I've had two bouts of mastitis. I've blamed it on many things...stress/fatigue, a distractible baby, a sick baby, etc. But, I wonder about OS too. I still block feed, but I double-pump 3 times/day 3 days/week at work. (I can't believe it never occurred to me that this might be a bad idea) Anyway, I am considering just pumping one breast per pumping session, but I don't know if this is a good idea as far as my freezer stash is concerned. Right now, I bring home 4 4-oz bottles per day. DD tends to reject the bottle at DC, but when she does eat, she usually takes no more than 3 bottles. Many times, she doesn't finish these bottles. So, if I were to start pumping only one breast, do you think I would bring home enough to supply her feedings at DC? I am terrified of her running out of milk! Any thoughts?