Danny has been constipated the last couple of days and I need to start him on milk of mag to clean him out but its been awhile and I don't remember how much I used to give him. Can anyone help? I put a call in to his CF nurse but they are all in clinic all day and won't bet back to me for awhile. For some reason 7 mls sticks in my head but I'm not sure. He weighs about 38.5 lbs. Any thoughts?