Beating the Bedwetting Blues

We have a little problem in our house, my oldest son has difficulty remaining dry overnight and he is nearly 5 years old.  When I spoke with my pediatrician she said that he probably has a small bladder and will grow out of being wet so we should continue to keep him in pull ups overnight.  Recently, I have noticed that he has been waking up saturated in the morning AND when I've begun checking him before he gets into bed he is wet.  Remaining dry while still awake clearly is within his control...so what to do with this information?

As a behavior analyst, I took a little data, although not as detailed as I should, but was able to glean that when his pull up was placed on 15 minutes or more before bed my son would often wake up with his clothing wet in the morning and at times would be wet before even going to bed.  If the pull up was placed on immediately before sleep he was less likely to wake up saturated.  This made me think, how could I apply reinforcement for eliminating in the toilet and dry clothes in the morning (I didn't expect a dry pull up yet as I do believe he has a small bladder and is a heavy sleeper)? 

My son loves his Leapster Explorer and we haven't purchased a new game in quite some time so this was the "carrot" we chose to use to encourage him to remain dry/use the toilet.  If he wakes up without his clothes being wet and uses the bathroom before going to sleep/as soon as he wakes up for two nights then we would buy him a new game.

The first night he went to the bathroom three times before bed and once during the night.  His clothes were dry and only his pull up was wet...success!  The second night he went to the bathroom before going to sleep, as soon as he woke up, and was minimally wet...another success! He was so excited to receive his new game and I was able to praise him for his success. 

The question that remains is will he be able to continue with this positive momentum?  Obviously we can't buy him a new game every two nights, so will a delay in reinforcement for a few days more be powerful enough?  The next goal will be five nights of going to bed dry and waking up without his clothing/bed being wet.  To be continued....