"Our three-year-old son has been toilet-trained for about four months, but he still has an accident every day or two. My wife says this is a normal part of the training process. It seems to me that a child his age should be doing better by now and that maybe he has a developmental problem. Which of us is right?"
Your wife is correct in saying the accidents sometimes continue for months after the toilet training process appears to be complete—even when a child is three or four years old. Such daytime accidents are part of learning new physical habits and should start to taper off by about six months after training. (Nighttime wetting can continue much longer.)
You are also correct, however, when you point out that quite frequent accidents in a three-year-old—particularly when they do not seem to be diminishing—may signal a physical or developmental problem.
Your best move is to talk with your child’s pediatrician about his toilet training history and current behavior and, if requested, take him in for a checkup. If there are no physical problems, your concerns will be put to rest. If there is a developmental delay or physical issue, your prompt attention will speed up the treatment process.