Stool toileting refusers trained at a later age than the rest of the group (P < .0001). Fifty percent (22/44) of the children who trained between 42 and 48 months and 73% (8/11) of the children who trained after 48 months experienced stool toileting refusal. Sixty-one of the study children developed stool withholding during toilet training.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pub...