urinating on bed and bedding

Hi,

Just after some advice really. My 7 year old son has autism and ADHD. Ive recently found that he has been wetting his bed and bedding. This is not while he has been asleep but while he is awake. I found it last night and he must have just done it as it was soaking. When we approach him he just says he "doesnt know" why he done it.

Is there anything we can do to try and talk to him or even help him

 

Thanks