Colin has written some interesting and helpful articles on the subject of bedwetting, and he's always extremely compassionate.
One such article discusses whether, if everything else has failed, a child or teen should be made to wear diapers to bed to ameliorate the problem, even if they don't want to.
If parents do opt for a return to diapers, I urge them to patiently explore every possible treatment option first, as being put back in diapers can be devastating, especially for a teen.
A bedwetter can at least go to bed feeling like a 'normal' kid, and if he wets, he can 'pretend' (or at least hope) that it won't happen again. Maybe a false presumption, but going to bed in diapers is the reverse presumption. Even if he doesn't wet, he still wakes up in diapers.
There are good arguments for requiring the chronic bedwetter to do what is necessary to mitigate the 'harm' his wetting is causing, such as disruption to his own and possibly a sibling's sleep, the extra laundry, and the odor of urine which can pervade a whole house or apartment. But also consider this:
A return to diapers can involve a devestating blow to a youth or teen's self-esteem, perhaps even worse than the bedwetting. (I realize other factors are involved.) Probably if that course is adopted, the earlier the better. Imagine a thirteen-year old in bed in diapers for the first time since being a baby.
Diapers and infancy are inseperably associated, along with related ideas of helplessness and lack of maturity. Ths could be a huge blow to a youth approaching or already in puberty whose thrust is toward independence and adulthood.
Diapers can be overwhelming in that they involve four senses- the thickness between the legs (especially if often recommended cloth diapers are used to alert to wetness), the sound from plastic or rubber as one moves, sights of diapers, pants, pins, perhaps a diaper pail, diaper rash ointment, etc., and the smell of baby powder. All of these sense experiences can be overwhelming and distressing.
If diapering is chosen, especially in the case where siblings are present, news will get out. A brother's friend will have cause to be in the laundry room where plastic pants are drying. Upstairs he'll open the wrong sock and underwear drawer by accident. Mom will have inadvertantly left laundered cloth diapers on top of the dresser. The diaper pail will be discovered. Brother will get mad and blurt. Someone with a toddler brother or sister will recognize the slight bulk under your track pants, and just know.
If parents decide to use diapers on resisting bedwetting kids, I think it's entirely defensible, but only as a seriously last resort.