Let's discuss one of the least scientific areas of pediatric medicine — potty training. Pediatricians have a lot of scientific evidence to guide us towards appropriate treatment of ear infections, asthma, and a lot of other problems. But when it comes to advising parents about potty training, pediatricians are free to practice their recommendations — as one of my colleagues likes to say —“unencumbered by evidence.”

If you ask a preschool teacher when to potty train your child, the answer may be “before they start preschool” (because, while it’s not easy to herd a room full of 3-year-olds to the bathroom, it sure beats changing diapers). But ask the same question to a pediatrician, and you’ll probably get a far more nebulous answer like “wait until they’re ready.” I know it feels like we say that just to frustrate you (and it indeed, it leaves you frustrated), but the truth is that in this situation there’s not a single correct answer.

There’s a lot of variability in the ages at which children are potty trained. Girls tend to pick it up slightly faster than boys. Children from lower socioeconomic conditions, as well as those in African-American families, tend to potty train earlier. And if you compare American kids to those in many other countries, we’re way behind the curve, mostly due to vastly different definitions of “potty trained.”

Here’s the main point: the time and effort involved with and needed for potty training depends largely on the child’s physical and cognitive development. I could potty train an 8-year-old in about 4 seconds (“Dude, pee in the toilet, or I’ll sell your iPad”). But if you start at 6 months of age, it’s going to be a much longer road. Somewhere between those two extremes lies the balance that will work best for you.

Here are some signs that a child may be developmentally ready for potty training:

• Some level of interest in going on the toilet — watching you or her siblings, talking about the potty, etc.;

• Dry periods of at least a couple hours (or an entire nap) between wet diapers;

• The sensation of having to use the bathroom, which he or she may express it verbally or by going to a “special corner” to do their business;

• A general distaste for wet or dirty diapers, usually manifested by coming to you for a new diaper while the old one is still warm;

• The ability to understand and follow simple instructions;

• A desire for independence and accomplishment, or to be like older siblings;

• The physical ability to walk to the potty, climb aboard, and pull pants up–or at the very least, down.

And whenever you decide you’re ready, here’s the strategy I recommend to my patients (and the one that worked for my kids). Feel free to modify it; as dogmatic as I can be when the evidence is clear-cut, in this case I take a much more relaxed approach to potty training.

Potty training requires some equipment that you may or may not already have (or that you may not have considered). Here’s a list:

• A potty seat (or 4). I prefer the toilet-mounted seats for home and the self-contained seats for travel/car use.

• Bathroom-size trash bags. These make great disposable liners to keep you from having to empty and clean the potty seat every time. They also keep your minivan from smelling like the men’s room at a football game.

• A step-stool. When using a toilet-mounted seat, a stool can make your child feel more secure.

• Small rewards that work for your child—M&M’s and stickers are popular choices. Make sure your child can chew/swallow edible treats safely. If you go with stickers, create a special place to stick them.

• Underwear/panties. Let your child pick them out—the process works better with some buy-in. Make a HUGE deal about how these are what big boys/girls wear and how important it is that they stay dry.

1. Set the stage

Introduce the idea with books or videos about potty training. Our family favorite was Potty Time with Abby Cadabby, but there are plenty of others out there. Demonstrate the process by putting underwear on a doll or stuffed animal, pointing out how dry they are, and showing how you take them off to sit on the potty seat. Even better, have an older sibling demonstrate; peer pressure is fantastically effective.

2. Save the date

Set aside a weekend (or a couple weekdays, if that works with your schedule—they won’t know the difference), and plan to stay home the whole time. Don’t make dinner plans or invite friends over. It’s just better that way.

3. Get [your child] naked

Going diaperless can be anxiety-provoking, especially for parents like me who cringe “every time a rug is micturated [peed] upon.” But it’s important, because being naked tends to make kids more aware of the need to go. It also prevents anything from getting in the way of a quick run to the potty.

Keep a full sippy cup nearby; a full bladder creates opportunities for learning. Take them to the potty every 15-20 minutes, as well as any time you just get the feeling they need to go. You can stay and watch or hang out around the corner if they prefer privacy; just make sure they don’t fall in. Reward successful attempts with the treats you bought, and don’t punish accidents—we’re working on positive associations. It’s OK to put the diaper back on for naps or at night, but devote your daytime activities exclusively to potty training.

4. Stay dry

After a day or three, once things are going relatively well, introduce the underwear. Stop the fluid overload to increase your chance of success. This is a huge step for your child and a major sign of independence. This is a huge step for your child and a major sign of independence[/pullquote]. Most toddlers around this age are very motivated by imitating older children, so really play up how special these “big-girl panties” are and how important it is to keep them dry. Put them on her and watch carefully for any signs of impending accidents. Promise a bigger reward (think: “toy store”) for making it through the day with dry underwear.

5. Be realistic

Until your child is able to hold it for extended periods of time, plan your activities accordingly. “Mommy, I need to go potty” may very well mean that it’s running down her leg. Encourage your child to go potty just before your leave the house, and limit your extended excursions away from home. Keep a portable potty seat in the car for easy access.

6. Phase out the rewards

The rewards should only last a month or two. Slowly wean the treats—maybe every other time, then once a day until you stop. If your 9-year-old still asks for an M&M every time he poops in the potty, he’s milking it!

7. Accept failure

Even the most successful potty-trainee will have accidents. Clean it up and move on. But if the whole attempt went down in flames, take a break for a few weeks and try again later.

Sometimes, as a parent, you have to pick a hill to die on; this isn’t it. Take some time off, and go back to step #1. You’ll get there. Also, don’t forget that daytime and nighttime dryness are not the same — bedwetting is considered perfectly normal until 5 years of age, and is extremely common even after that.

Finally, once your child has their rhythm down, it’s time to celebrate. You’ve rewarded your child during this whole process; now reward yourself, because this is one of the more frustrating tasks of parenthood, and you made it through. Pour yourself a glass of wine and take a long bath with a book [that doesn’t have button-activated flushing sounds], or find a babysitter and have a date-night. You did it!