Robin Nolan’s son finished potty training at age 2-1/2 but began having accidents again when the family welcomed a new baby. The Carson City, NV, mom had heard this could be common, but it was a definite frustration — especially when coupled with the demands of a newborn infant.

Having multiple accidents or refusing to use the toilet after having successfully finished potty training is called "regression," says Dr. Charles Shubin, director of pediatrics for Mercy Family Care in Baltimore, MD, associate professor of pediatrics at the University of Maryland and assistant professor of pediatrics at The Johns Hopkins University. Regression, while frustrating, is a common struggle many parents encounter, and it has a variety of causes. But don’t worry — you can get back on track with training despite a bout of regression.

What Triggers Potty Training Regression?

Experts say a major reason for regression is the addition of a new brother or sister to the family. “The sibling rivalry that ensues motivates the older child to act more like the baby to get the attention back [that] the baby has taken away,” Dr. Shubin says. “Attention-getting is frequently the basis for regression, even without the arrival of a new sibling.”

Another possible cause for regression could be an infection. “A urinary tract infection can make it difficult and painful to control the bladder, so this can manifest as regression,” says Dr. Cara Familian Natterson, a pediatrician from Los Angeles, CA.

And while regression can happen for many reasons, it’s usually stress-related, says Michelle LaRowe, a professional nanny with more than 12 years of experience.

“An abrupt change in routine, starting at daycare, welcoming a new baby into the home or any other major life change will throw the little one’s mind and body out of whack,” says LaRowe. “Having an unpleasant experience using the toilet, such as a painful bowel movement, or being teased or disciplined for an accident at daycare also could be the cause. Some older children don’t want to take a break from playing and end up getting to the potty too late.”

Getting Back On Track With Potty Training

Dr. Shubin advises getting back to the basics in order to get back on track with potty training. “Return to the basics of behavior modification: clear expectations, clear responses to the expectations being met (rewards, especially attention) and clear responses to the expectations not being met (ignoring the unacceptable behavior).”

Dr. Natterson says positive reinforcement is key. And she’s quick to point out that negative reinforcement can have a bad effect on your child’s progress. She says, “If your child suddenly gets lots of attention for accidents or regressing to a diaper, he may become invested in that behavior. Sure, he would like positive attention, but [he or she] will take negative attention over being ignored.”

LaRowe says reading books to your child about potty training will offer additional positive reinforcement. She also recommends starting a reward or sticker chart that will visually show your child’s progress and allow her to take pride in daily accomplishments.

“Get back on track by sitting on the potty during regularly scheduled times as part of your daily routine, every three or so hours,” LaRowe says. “You can also try to catch him when he looks like he needs to use the potty, remind him to use the potty when he’s playing and provide lots of positive, purposeful praise during this time of getting back on track.”

As for Nolan? She focused on giving her son the extra attention he craved and relied on the start of school — it served as both a deadline for his potty training efforts and a sign that he was now old enough to use the potty. “For school, I put him in ... underwear and sweat pants he can easily take down to go potty,” she says. “He seems empowered now, using the toilet on his own, even at home.”