My grandson has a problem with wetting the bed. He is now on medication and doing better. If he takes it around 7 or 8 and goes to the bathroom before he goes to bed at 10:00 he will not wet the bed. It seems as if he takes it later it doesn't have time to take effect. He usually wets within the first 2 hours after falling asleep.
He used a blow up mattress for years, now he has a two yard piece of plastic that covers his bed. They sell it buy the yard at JoAnn's. The pads that most people use do not absorb well enough for him.
Good Luck
Syl