J.C.
My DD only drinks water and milk. I've never given her anything else. I would not worry about no juice - its really not that good for them anyhow. Too much milk can make them constipated though as you allude to. I can't remember the max amount at 1, but I think its no more than 2-3 cups per day. I say offer milk, but once he's drank his fill, only offer him water (my DD really like the Nuby sippy cups with the soft tops). Some kids like it with just a touch or juice in it. But a lot just take time to adjust to anything other than milk since that;s basically all they have been drinking their lives!