2 week old

Do you give him any water? If possible, I'd just mix it in water or with a little breast milk and put it in a bottle for him.

It's normal for breastfed babies to go up to a week without a bowel movement. If he isn't drawing his legs up,straining and crying,he probably isn't constipated

Many people are against Kyro because they say there's the possibility of botulism in it.  I loved it. 

  Does the pediatrician have any suggestions?

If he's not crying or looking uncomfortable he's fine.  If you're worried try rocking his legs gently back and forth this can help move gas along.

It could actually be gas. Trying bicycling his legs. No Karo... even the Karo company says not to do this because it's a botulism risk same as honey.

Beware blowouts, though! They can be very very messy!

Try putting him in a warm bath, that usually worked with my daughter. Karo syrup does work sometimes (recommended by my pediatrician). He isn't old enough for prune juice or anything like that. If he starts straining and crying trying to make a bowel movement you can take his temp rectally (it usually works). My son is lactose intolerant and even has issues with his Soy formula, he gets constipated all the time and the only thing that helps him is to do the rectal stimulation. We have tried everything else for him with no success.

and baby doesn't need any water
your milk is enough fluid for him

Your milk is perfectly fine I wouldn't add anything to it at all, like the other mom mentioned it is ok for no bowel movement for a few days but if it is over a week then go to the doctor. Try holding his legs as if he is in a sitting position and see if he has a bowel movement that way, I had to hold my DD for up to 10 minutes like that to get her to go to the bathroom, and I would hold her over the sink/toilet just in case because she did not like going in her diaper and would just hold it.

My niece had to GENTLY stimulate the baby's anus with a q-tip to get the poop moving. DO NOT put the q-tip in the anus, just gently touch the outer area with the q-tip. It worked for them. And this was told to them by their pediatrician.