the most common averages for growth surts are 2 wks 3 wks 6 wks, 2 months, 3 months and 6 months, they generally space out a bit as they get older.
i dind't have actual pain with letdown unless i wasn't actually feeding, then it was VERY tingly (kinda like when youre arm or foot etc goes to sleep). it stopped hurting at all when i didn't have such a massive oversupply of milk.
the rice cereal really doens't do much most of the time for night time. good info at
kellymom :: Breastfeeding and Parenting though i don' thave the link handy right this second.
rice ceral also tends to "constipate" babies, and not only that, the extra iron it is "fortified" with can actually displace the iron that is easily bioavailable in human milk. there isn't a lot of iron in mama's milk, but it is balanced just right so that it is absorbed, iunlike in aim or fortified things where they cram tons of iron into it so that some gets absorbed.