I feel your pain. Here are a few ideas:
1. I tried the kyro syrup and it worked like a charm.
2. Prunes/prune juice helps too. Sometimes works too well, but you will be grateful when that happens.
3. In addition to fruit, I found giving my daughter more liquids helped too. I made sure she had whatever formula/milk she needed for the day, but then I also supplemented watered down juice (especially prune juice) throughout the day really helped. My pediatrician recommends no more than 4 - 6 oz of juice per day, so I mixed very little juice with lots of water to keep her well hydrated.
4. When your child is struggling to 'get one out', rather than having to 'pull it out' (which my husband and I had to do one day), try sticking your son in a warm tub. Give him a 5 - 15 minutes in a little warm water and I pretty much guarantee he will probably poop right in the tub. Then just pluck him right out and clean up the mess. Not pretty, but has worked for me a few times when my daugther was really struggling to go #2.