If my 8 year old son pooped his bed wetting diaper I would make him wear diapers all the time.
I would put my 8 year old son in thick diapers and treat him as a toddler like Tommy Diaper Boy.
I would dress him in just his diaper and shirt and make him suck on a pacifier, feed him in a highchair and make him sleep in a crib.
I would also make him drink formula from a baby bottle.

