Q. For six years I’ve been the nanny for three active little boys: a 6-year-old, who is usually at school, and his 3-year-old twin brothers, whom I watch from 8 in the morning until 6 at night, four days a week.

The parents and I casually began to potty-train the twins seven months ago and started concentrating on it in March when they turned 3, but the results have been mixed. One of the twins is completely potty-trained and wears a pull-up only at night. The other one pees in the toilet but holds in his bowel movements for two to three days. Then when things get hectic in the house, he sneaks away to poop in his underpants, then immediately tells his parents or me what he did.

Instead of punishing him or treating him badly, we are really patient. We tell him that we’re disappointed and say things like, “Oh, I wish you had put your poop in the toilet” or “Come to us the next time you want to go, honey; we can help you.”

We’ve also tried all the usual solutions, and we’ve promised him a favorite food, a new toy, a trip to the zoo and other bribes if he poops in the potty. He seems interested at first and says that he will try, but he still won’t tell us when he has to go, so he hasn’t gotten any rewards. That doesn’t seem to bother this smart, sweet, sensitive child, but I think the potty problem may bother him more than he admits. He has been stuttering a little more and is more aggressive toward his mom and brothers.

I sure hope you can help me figure out what I can do to help this child.

(Hadley Hooper/For The Washington Post)

A. What a good nanny you are. The parents are lucky to have you because you care so much about those three little boys.

A little boy who holds in his poop for two to three days is probably ready to use the pot, and he’s probably stuttering more and acting more aggressive because he’s ashamed that he isn’t using the potty yet.

There is a reason for everything a child does, every tear he sheds, every tantrum he throws and every poop he makes in his underpants. The less he knows about a subject, however, the weirder his reasons are.

Sometimes a child won’t poop in the toilet because he’s afraid that he’ll fall in and go down the pipes when it’s flushed. This is a common fear, since a 3-year-old’s understanding of weight, volume and measurements is really wretched.

Another child might think that his poop is part of himself and that it isn’t right for him to get rid of it. This is the child who needs to know that his intestine draws vitamins and minerals out of his poop, sends these nutrients to every part of his body and then throws the rest away, just like you throw away the bread wrapper after the boys have eaten the bread.

And then there is the super-smart child who’s interested in the city’s plumbing as well as his own. Although he may not ask, he still wants to know where the poop goes when it leaves the bathroom. What happens next? This child will never be content until you show him the manhole cover on the sidewalk and tell him about the sewer pipes that live underneath it. You may even have to take him to the water treatment plant and ask the manager to explain this system to him, or take him to the reservoir so he can see that the water has gotten clean and clear.

Every child needs to know how things work, but this child needs to be involved even more. After you have wiped his bottom and put him in clean underwear, ask him to dump his poop into the toilet and then to flush it away, because this won’t seem so threatening after he’s done it a few times. He will also feel relieved because he knows in his heart that he should try to solve a problem if he was the one who caused it.

To find more ideas, read “Potty Training Boys the Easy Way” by Caroline Fertleman and Simone Cave (DaCapo, 2009, $12) and to amuse the child, read “Potty Animals” by Hope Vestergaard (Sterling, 2010, $15) to him.

And if none of this works, don’t worry. This little boy will be trained by the time he’s 4. Somehow, children always are.

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