10 yr old boy wets bed

Hello,
I wondered if it was normal for a 10 year old boy to continue to wet the bed at night. He always has done this. I took him to a pediatric urologist. The nurse practitioner told him to void and did a bladder scan on him. There was about a 50cc residual. She decided that he should be on a bladder and bowel training program (which included chocolate exlax) with him but told him that he is the one that will need to "want" to stop wetting the bed in order for it to work. Well, this didn't go over well and so it didn't happen. He sleeps in "pullups" which are really adult briefs because he is too big for pullups. I have a waterproof pad that he sleeps on as well because the quantity of urine is a lot and it usually goes through the pullup and onto the bed. He is limited liquids by 6pm at night. And he is a very sound sleeper. He does not wake up at all during the night, not even for any loud noises that may have happened.

I have been told that sometimes boys do not stop wetting the bed until they reach the age of 13. Is this true? Is my son still in the "ok" zone? Or do I have a large problem on my hands and need a second urologist opinion??

My husband (my son's step father) gives him a very hard time about wearing a "diaper" and that he should not be wetting the bed at this age and that he is doing this on purpose. I know he is not.

Any input would be great.
Thank you in advance.