The children's section of the book has two stories, one for boys and one for girls, about children using an imaging or visualization process to end sleepwetting. Both stories are written at about third grade readability level, but could work read aloud with children six and up who are not reading at that level yet. The visualization concept is not childish and can work for teens and adults. If you decide to try this, you will probably want a personal copy because rereading one or both stories almost every night is part of the process.
GoodNites® disposable absorbent underpants come in boy and girl styles in two sizes,
'Medium' [45 to 65 pounds - 20 to 30 kg]
'Large/XL' [65 to 125 pounds - 30 to 55 kg]
GoodNites® are marketed in the UK and some other countries under the name Dry Nites®.
Pampers® now makes UnderJams® for overnight use in similar styles and sizes as well as size 7 disposable diapers for children over 40 pounds.
Several chain stores in the US have similar house brand disposable absorbent underpants usually in one all-white style with two or three sizes. Their prices are generally a bit lower and bulk quantities may be available.
washable padded cloth pants, waterproof overpants, and one-piece combinations are available from several incontinence products sites on the Internet.
ABC's of Parenting - look under their topic 'bedwetting' for a list of other responsible resources
disclaimer:
I am NOT a medical professional and do not offer advice that should be taken as medical or therapeutic in intent. Always consult a doctor for medical diagnoses and treatments. I have researched the area of teaching bladder control and managing bladder disabilities as part of volunteer work with incontinence support organizations and families of children with disabilities. I am a writer, actor, storyteller, former children's bookseller, and parent of two young adults. I serve as one of the moderators for the kids' e-mail list EnuresisKids.