Proud parents turn anxious and shrewish. Cherubic infants become stubborn little demons.

It's potty training time.

Not only do ordinary folks face a challenge. Pediatricians have issues with their own offspring.

That was obvious this month when about 75 attendees at the American Academy of Pediatrics meeting in Atlanta showed up for a 6:45 a.m. workshop called "Turning Toilet Resisters Into Super Dooper Poopers."

When the time arrived for questions, participants asked not about patients' problems but their own thwarted efforts.

Potty training expert extraordinaire Alison Schonwald of Children's Hospital in Boston was there to offer advice. She's a pediatrician and author of "The Pocket Idiot's Guide to Potty Training Problems" (Alpha, $9.95).

"There's nothing stronger," she says, "than a child's will not to poop."

Being toilet trained is a process involving many steps, she says, from knowing when it's time to run to the bathroom to washing your hands. Parents whose children are lagging behind should consider which steps their kids can already accomplish and work one at a time on ones that haven't been mastered.

Schonwald, who works with children 4 and older who haven't mastered toilet training, assigns her patients a "job" at each visit. It may be just getting into the bathroom or sitting on the johnny with the lid down.

The reward for each successful step should be small, she said. If the promised reward is too great, the pressure and stress on the child may rise accordingly.

She never criticizes or punishes a child for accidents but tries to understand the fear or hesitation.

She never takes a child backward to diapers or pull-ups who is already in big-kid underwear.

She advises parents not to send mixed messages by "babying" a child on one hand and nagging him to be a big boy on the other.

And don't tell the child, "You can't go to preschool until you can use the potty" unless you're sure he wants to go to preschool.

You may have just offered him a means of escape.