Also.... GET SOME PULLUPS!
What is WRONG with you people? Just in case anyone else is having the same issue, punishing a child for soiling their pants is the WORST thing you could ever do!! A child doing that ALONE is a blaring red sign that something is very wrong - you don't fix psychological problems by spanking them away! But in addition he has nightmares and bites his fingers until they bleed? That poor child! Somebody in the thread wants to know how it turned out - my guess is CPS took the kid!!
I know you wrote a post about your son peeing his pants and biting his nails back in 2008 but I am curious as to how he is doing? I hope he is doing much better. I know medications can have terrible side effects, however I have worked with many children undergoing stress that have had symptoms like your sons. Physical punishment isn't the way to go, even though you might have been or may be frustrated. He does need a good counselor and to maybe look into different medication options. It sounds like he is struggling with anxiety rather than ADHD and the stimulant ADHD medications only intensify these feeling of anxiety. A great medication option for this is Straterra (a non stimulant ADHD medicine that helps with anxiety as well) and Vistaril (an antihistamine used to treat anxiety). I will keep you guys in my prayers. I hope he is much better by now.
I know from experience that ADHD medications can sometimes cause nightmares. As with my oldest son.
The nightmares and bed wetting without meds, though, would be another story all alone. I agree about the therapist!! I'd be checking into it and they can determine if the nightmares are related to the meds.
I'm with brooke above - something seems to be making your child VERY anxious, unsettled and changes in previously continent children can indicate that something is seriously wrong. Now I'm not saying this is the case, but abused or bullied children can exhibit all of those behaviours. I think that seeing a therapist would be a really good thing - not only can they help with fixing the behaviours but they might be able to get at the root of what is causing them.
Frustrating as it may be, try not to spank or punish him for the incorrect toileting - this will worsen his anxiety (and as you have found) make his lie/try to hide it because he knows its wrong. I think that he is not doing to be naughty... I think that he probably genuinely cant help it. Try to be really positive and reassuring about going to the toilet and praise and reward him hugely when he gets it right.
good luck, I really hope things get better for your wee one :)
Have you considered having him see a therapist? This sounds pretty serious. I don't think this is something you will be able to take care of on your own.