Anne--I have seen a number of preemies who nurse short periods of time and frequently break the seal. If she seems to be getting enough milk and output is fine, I would look into overactive MER. I see quite a bit of it and when you add pulling off + colicky baby I always think overactive MER. I would suggest that she see an LC to verify this as tx for this problem could be disastrous if it is indeed NOT the problem. Hope this helps! Diane DiSandro, BA, IBCLC Audubon, PA--LC in private practice