A.M.
If he doesn't seem to be in pain, the length between bowel movements shouldn't be a concern. Babies are very efficient at using the food we give them. Sometimes, there isn't enough waste to vacate for a few days. If he does seem in pain, you can give him a small amount of dark Karo syrup in water. I would start with a 1/4 tsp in 2 oz. and then increase after a few days if it doesn't seem to be working.
Hope that helps!