You won't like what I have to say, but I will say it anyway. I have sleep problems, and come from generations of them. My mother says that I am "on the vampire shift" because I just don't sleep well at night. I never have.
Sleep hygeine actually IS as important as she says. IF you can get a routine, make a sign with the times, what he should do, and then stick to it? You actually might see a HUGE change. I thought it was BS for years. I finally figured out that until I tried it, I was NOT going to be able to access other help for the problem. It didn't cure my problems, but it did make a big difference.
WHen we implemented a plan for Wiz when he wasn't sleeping, it made a big difference. Took a rough couple of weeks, but it helped. It is NOT a magic fix by any means, but it helped a LOT. One of the BIG key things is to NOT allow him to play when he wakes up in the night. My husband used to be confused because if the kids woke up in the night and he let them watch tv, they then got up every night. But if I got up and did NOT let them play, watch tv, even read (that was really hard because we are total reading addicts in my family), then it was a one night thing and sleep was had by all. We used audiobooks of soothing, non-violent books to help when our kids were going to sleep. My dad recorded the old Uncle Wiggily stories for my kids and WOW he has this deep, relaxing voice that is amazing.
THe other part of this is that MAYBE sleep hygeine won't help. But you will NEVER know until you try, and you will NEVER get more help until you try and it fails. I have seen data that as many as 80% or more of those who think they have insomnia actually just don't go to bed and close their eyes and lay there to try to sleep - and when they do this they DO fall asleep.
Unless your child already has good sleep hygeine, you have NO way of knowing it won't help. It is a change, and sets some limits which won't be fun the first week or two. In time it will either help or it will show the dr that you gave it a darn good try and need more help. But the ONLY way to get that more help is to jump through their hoops. Annoying, but you could be surprised. I know I was.
by the way, if a child gets up at 2 am to play and is allowed to play, he WILL get up over and over again. I had the HARDEST time getting husband to grasp this. He would let the kids watch tv and then be shocked when it happened the next night. So I would make him deal with all kid problems if he got up and let them play rather than making them go back to bed, listen to an audiobook or classical music, and wait until morning. Actually classical music is often amazing at putting kids to sleep. I can remember try running crying from a store in a mall because "It's not bedtime!!" and they were playing the same Mozart that we played at bedtime each night. It has been 7 or 8 years since we used it regularly with him and STILL it will get him to sleep if he is having problems of feeling yucky.
The WORST that good sleep hygeine can do is establish a routine for bedtime. If that happens, you can then go to the doctor and say "we have done this for a month with NO results. Now can you help us?" Sometimes that has to be done even when it is a PITA.