I'm a pediatric urologist, and here's my response to the parents of Izabella Oniciuc, the famous potty-trained 6-month-old: I know you are excited about your precocious pooper, but watch your daughter closely, because she may be headed for trouble.

According to the Daily Express article, Izabella "refuses to go to the toilet unless her parents lift her on to the potty." If this is true, it means Izabella will hold her poop or pee if her parents aren't at the ready to hoist her little bottom onto the toilet.

The Oniciucs may be thrilled and proud that their daughter knows how to hold her pee and poop, but from my perspective, they should be concerned. For proper bladder development, young children need to pee and poop without inhibition. For most babies, wearing diapers facilitates unconstrained elimination. (For the record, I receive no money from the diaper industry, and I think cloth diapers are terrific.)

Chronic holding is a damaging habit, and in my experience, children trained early -- especially before age 2 -- are more prone to developing this habit than kids trained around age 3, though kids trained later are certainly not immune from holding, and early trainers are not destined to become holders.

In toilet-trained children, chronic holding is the root cause of virtually all toileting problems, including daytime pee and poop accidents, bedwetting, urinary frequency and urinary tract infections. Published research, including our clinic's 2012 study published in Urology, demonstrates that when you clear up clogged kids and prevent them from holding, the accidents, UTIs and bedwetting episodes almost always cease.

Our study simply confirmed results from a remarkable series of Canadian studies led by Dr. Sean O'Regan. These studies showed convincingly that children with wetting problems were severely constipated, despite showing few or no outward signs, and that treating constipation resolved the wetting and UTIs in dramatic fashion.

For reasons I explain in depth here, holding is epidemic in contemporary Western culture and on the rise. My clinic is booked solid with kids whose holding habits have led to all kinds of problems. A high percentage of these children were, like Izabella Oniciuc, out of diapers before age 2.

Parents Are "Lazy"



If you read the comments about the Izabella article, you'll get a sense of the typical arguments in favor of early toilet training: Kids are smarter than we give them credit for! Parents are lazy! They train early in India and Kenya! Diapers are bad for the environment!

Let's first dispense with the intelligence issue. Izabella's mom, Raluca, told the Daily Express, "Babies are not stupid... I think she responds well to everything because I've listened to her from birth."

In truth, mastering the toilet has nothing to do with brainpower. Parents who wait until later to train their children aren't treating babies as "stupid" and neither are they lazy; they're wisely allowing their child's bladder to develop in a healthy manner.

And kids who trained early are actually too clever by half! You see, though kittens aren't any smarter than human children, they can easily be taught to go in a litterbox on time because it would never occur to them to delay pooping. It takes an evolutionarily advanced brain to realize that by holding in their poop, you can play Rapunzel for a few more uninterrupted minutes (or hours).

Babies and toddlers simply don't understand the importance of eliminating when nature calls. Knowing how to poop on the potty is not the same as responding to your body's urges in a judicious manner.

Once kids learn to put off peeing and pooping, essentially the definition of toilet training, they tend to do so often and for as long as they can. Children -- and I mean all children -- don't like to interrupt their lives to use the bathroom. This is problematic, because each time you squeeze your sphincter to prevent the release of pee, you create resistance in your bladder.

What happens when muscles go up against resistance? Exactly what happens when you train your hamstrings at the gym: They get thicker and stronger.

But unlike muscular hamstrings, a thicker bladder is a bad thing. It has a smaller capacity and its sensation mechanism goes awry. When a child habitually delays peeing, over months and years, her bladder wall becomes more muscular. Eventually the bladder can get so strong and irritable that it empties without any input from the child.

Chronically holding poop, a problem exacerbated by Western kids' low-fiber diets, compounds the damage. A mass of poop forms in the rectum, right behind the bladder, and can stretch the rectum from about 2 centimeters in diameter to 10 centimeters or more.

There's only so much room in the pelvis, so the bladder gets squeezed out of the way and can't hold as much urine. What's more, the nerves controlling the bladder, which run between the bladder and the intestines, can get irritated when the intestines are enlarged, causing unexpected and unwanted bladder contractions -- in other words, mad dashes to the toilet and accidents.

Perhaps you're thinking: My kid isn't constipated -- she poops every day. Well, many constipated kids poop regularly, even multiple times a day. Large poop masses in children typically go unnoticed because looser poop oozes by and finds a way out more easily than the hard stuff, giving the impression that the child has fully eliminated.

This is what happened with Zoe Rosso, the 3 ½-year-old who was suspended from a Virginia preschool for "excessive" potty accidents and who is now my patient.

As it turned out, Zoe had a poop mass the size of a Nerf basketball stuck in her rectum, though both her pediatrician and pediatric urology clinic missed it. Because Zoe's bowel habits were normal, they did not X-ray her.

Perhaps you've read about studies demonstrating that late training causes more accidents. Maybe you want to post them in the comments section. Don't bother! I've read them all. Instead, call up the authors and ask if they used X-rays to make sure the children who trained late weren't also constipated (a common cause of the accidents and also of late training). Not to spoil the surprise, but they will tell you, "No, we didn't."

Here's something else Izabella Oniciuc's folks should know: Chronically holding pee and poop also causes urinary tract infections. The less often a child pees, the more opportunity for infection-causing bacteria to creep up to her bladder. And if this kid is also hauling around a hefty load of poop, she's harboring about a gazillion more times the bacteria than when her rectum has been emptied. Since the bladder is only a couple of inches from the rectum, the offending bacteria have a short trip to make, crawling through the perineal skin and into the vagina and the area around the urethra.

Do you know how often I see children who are still in diapers and have recurrent UTIs? Never. That's right, never. Do you know how often I treat newly potty-trained children for recurrent UTIs? Every day. These kids fill a quarter of my clinic. This is not a coincidence and demonstrates quite clearly that toilet training in very young children can be harmful. Kids in diapers don't hold; many toilet-trained children do.



But They Don't Wear Diapers in China

What about the argument that in China and Africa and India children do not wear diapers, nor have children for the vast majority of human history? Well, in the developing world, kids aren't eating Froot Loops for breakfast, snacking on Fritos, lunching on chicken nuggets and chocolate milk and eating mac and cheese for dinner. Low-fiber diets make for hard, painful stools. To avoid the pain of elimination, many kids hold.

What's more, in much of the developing world, toilets aren't the norm; instead, people squat, a position that, research demonstrates, makes elimination much easier. And when you don't need to worry about finding a toilet (behind a bush will do), there's less reason to hold. It's all about access.

In addition, in most developing countries, 2-year-olds don't typically go to daycare or preschool. Perhaps Izabella Oniciuc will be staying home with mom, but early-trained children who do attend preschool are at risk for developing toileting problems, particularly if these schools, like Zoe Rosso's, require potty training by age 3 and don't allow the safety net of a pull-up.

Think about it: You're placing a little one in an unfamiliar environment where, for possibly the first time in her life, she has no family members around for half the day, and you're expecting her to interrupt her teacher during the story circle and announce that she needs to use the toilet or to climb out of the fort she's just built with her friends and make her way over to the potty. Whoever thought that was a good idea has surely never set foot in a pediatric urology clinic.

Making matters worse, many kids trained early are ill-equipped to deal with the sub-par restrooms and restrictive bathroom policies that may await them in elementary school and beyond. I have countless patients who have developed the capacity to hold their pee and poop from 7:30 a.m. to 4:30 p.m. -- and have developed serious bladder problems and recurring urinary tract infections because of it. School restrooms and policies that limit bathroom passes are no small contributor to our potty-problem epidemic. (Check out projectCLEAN.us to get an idea of just how bad this problem is.)

In short, it's silly to make arguments based on other cultures and other periods in history. First of all, the most primitive form of toileting is going wherever and whenever you need to (think of any wild animal), which diapers actually promote. There is nothing natural about using a toilet. Second, I treat kids who live here and now. And no, I am not including in this group the elimination-communication kids who eat unprocessed diets, are homeschooled and never leave their parents' sides. If Izabella Onicius is one of those kids, she may do just fine. But that's a big responsibility for a parent to take on, especially given that constipation can be so easy to miss.



Make Sure Your Kid is Pooping Hummus

I don't believe in toilet training children for the purpose of meeting the requirements for a school or because Mom and Dad are tired of changing diapers or because it seems cool. I believe in potty training when kids are ready -- when they show an interest and can tell you when they are peeing or pooping -- and I believe that few kids are genuinely ready before age three.

Nonetheless, I'm sure some younger children are ready to toilet train, just as some kids are way ahead of the curve for other milestones, whether it's walking, talking or riding a bike. If you feel certain your child is among them, or if you are absolutely set on sending your child to a school that requires three-year-olds to be trained, following is my advice for doing all you can to preempt problems:

•Make sure your child's poops are mushy before you start training.

I mean mush, like mashed sweet potatoes or hummus. The sure way to sabotage the process is to try to toilet train a constipated kid. If your child's poops are formed, like logs or pebbles, or become formed during the toilet-training process, your child is constipated, and you should get her pooping chocolate pudding for several months before you attempt training. Extra-large poops also are a red flag.

•Watch your child like a Secret Service agent once he is out of diapers. (This applies to all newly trained kids, regardless of when they trained). Have him on a peeing schedule so that he never goes more than about two hours without using the toilet. Have him sit on the potty to poop after breakfast and dinner. Never ask, "Do you need to go potty?" All kids will say no. It's your job to instruct your child to go. Don't lose track of the last time he pooped and what his poop looked like.

•Keep an eye out for signs of developing problems. The potty dance isn't cute or funny; it means your child is holding. So does sprinting to the bathroom. You need to nip these problems in the bud, no matter what your child's school policy requires.

Parents of kids who train on the later side are frequently subjected to ridicule. So I was glad to read the following comment from a mom who responded to the Oniciuc's story: