The effects of undergarment type on the urinary continence of toddlers.

Lecavalier et al. (2006) watched five toddlers in daycare. The kids wore diapers, pull-ups, or real underwear on different days.

Staff recorded when each child stayed dry and used the toilet. No extra training was given.

Two children had fewer accidents when they wore underwear. Two stayed the same. One child showed small gains only after teachers added praise and practice.

The team called the result “mixed.” Underwear alone was not enough for everyone.

Byra et al. (2018) later worked with two preschoolers with autism. They added simulation and praise for wiping. Both kids learned the full bathroom routine and kept it at home for six months. Their study extends L et al. by showing that underwear plus skills training works for children with ASD.

Webb et al. (1999) used short practice sessions to teach catheter use. Like L et al., they showed that simple behavioral steps can give young children more control over toileting.

Moxley (1989) treated bed-wetting with alarms and parent coaching. That paper and L et al. both chase dry pants, but A worked at night and added family support. The two studies do not clash; they target different times and use different tools.

If you run a preschool classroom, do not assume underwear will fix accidents for every child. Start with underwear, track data, and be ready to layer in praise, practice, or full skills training if gains stall. L et al. warns us that one size does not fit all, while Byra et al. gives you the next step when you need more power.