Evaluation of a new method of toilet training (TT), meaning TT in group in daycare centers, guided by a TT expert. Children are included based on signs of readiness for TT.

A cluster randomized controlled trial (CRCT) was established in daycare centers. Clusters of participants (per daycare center) were randomly allocated to an Intervention group or a Control group.

Evolution of the TT process was monitored in the daycare center until the child was considered to be fully toilet trained (or 'clean') during the day (this means wearing undergarments, conscious of the need to void and initiating toilet behavior without reminder of the parents with a maximum of one leakage a day [9]).

Daycare workers evaluated the TT process of all participating children on a weekly basis. Parents were asked to fill in an online questionnaire when their child was completely toilet trained.

Inclusion Criteria:

• knowledge of the Dutch language
• aged between 18 and 30 months
• not yet toilet trained during the day and night (diaper dependent)
• Parents of the children had to be motivated to participate in the study and willing to invest time and effort in continuing the TT at home
• Children met at least two of the following three signs of readiness: the child expresses a need to evacuate and shows awareness of the need to void or to have a bowel movement; the child insists on completing tasks without help and is proud of new skills; or the child can pull clothes up and down in a TT related context

Exclusion Criteria:

• Children with urological, neurological, organical or behavior problems