Just that really. He's not constipated as he has plenty wet and dirty nappies but he is quite a windy baby. Up until a few nights ago we were in a fairly decent routine of him waking every 3 hours for food, burp, change, then back down again. Now he's added straining and grunting while he sleeps in between.
He's a good feeder (has gained weight continuously since birth) but doesn't feed for long periods (less than 10 mins). I have a pretty fast letdown so I'm sure he's getting plenty. He can occasionally fuss at the nipple with hands everywhere and then he gets frustrated.
Any ideas?