Q. Our 3-year-old is only partially potty-trained -- she refuses to have a bowel movement on the toilet. What can we do to encourage her?

A. As a parent and a pediatrician, I know how frustrating such a roadblock can be. There are several explanations for why your child might be wary of taking this next step: Often, kids are afraid they're losing a part of themselves when they see their stool "swoosh" down the bowl; they've experienced constipation and associate all bowel movements with pain; or they're simply going through a contrary phase. Whatever the reason, here are some ways to help:

* Give her plenty of water and such high-fiber foods as whole grains, fruits (especially prunes), and vegetables, to keep her stools soft.

* Make sure she's comfortable. If your child's learning to go on an adult toilet, plant her feet on a step stool for support. (When kids' feet dangle, their rectal muscles tighten, which makes it difficult to go.) Or let her pick out her own potty -- children are more likely to use one they've chosen.

* Watch for signs that she's about to go -- such as grunting, squatting, and peering down at her pants -- and immediately usher her to the bathroom. Even if she poops in her pants or diapers, at least she'll get used to being in the right place.