Grass should be good, yes.
Tinyamounts of a variety of food may be your best bet. A baby bunny's diet really depends on what s/he's used to, so best to just follow your instincts and feed him what the market people feed the local rabbits. I suspect that grass ispart of their diet.
Also, hewill be more inclined to eat what's familar.
Don't load him up on fruit and other treats, and avoid breads and cereals -- just give him a few flakes of oats, not a bowl full.
Milk isn't that great, but my friend George fed all his bunnies a baby formula for months, and they were all fine, it's not always a problem. Did he like themilk? I'm not sure about that one, the danger isthat it's easy to throw a baby's gut out of whack at that age with anydiet changes. But aside from the gut imbalance, the milk issue from what I understand is more that bunnies grow intolerent tolactose as they age.
Rule of thumb is that you have to start out feeding only tiny amounts of any new food and carefully watch their output -- if they have mushy poops, you have to stop feeding it to them.
As far as no poops goes, as long ashe's eating, he should start pooping. Just make sure s/he's has access towater. Are you giving her water in a bowl? Some baby bunnies may not know how to work a water bottle.
If he really isn't pooping, you're going to need to keep him moving, rub his tummy, and make sure he drinks a lot.
Don't worry about him sleeping a lot, babies do that. They're only active and hour or two a day when they're that young.
Hope he is okay! This bunny is very young and that may be a problem, butit's awsome you've taken him, he has his best chance with you.
Let us know how he is.
sas :clover: