Constipation and Withholding During Potty Training
The hidden variable behind so many potty training struggles — the withholding cycle, the signs to catch early, and what to do, from a Canadian paediatric potty training consultant.
The short answer. Constipation is the single most common hidden variable behind potty training problems, and it’s easy to miss because its leaking, accident-like soiling looks exactly like a behaviour problem. It runs on a self-feeding withholding cycle: one hard, painful poop teaches a child to hold it in, which makes the next poop harder and more painful. You cannot successfully potty train a constipated child until the constipation is addressed — treat it first (or alongside) with your healthcare provider’s guidance, ease the pressure on training, and be patient while the cycle breaks.
🩺 How this was checked. Written by Milos and fact-checked against current Canadian Paediatric Society, Health Canada, and AAP guidance (see Sources). Independent clinical review is being added — this page will carry a named medical reviewer once that’s in place.
The cause parents almost never suspect
When potty training goes sideways — accidents, refusal, regression, a child who simply will not poop — parents look for a behavioural explanation. Is my child being defiant? Lazy? Not ready?
Very often, the real answer isn’t behavioural at all. It’s constipation. Constipation is the single most common hidden variable behind potty training problems, and because its most telling sign — leaking, accident-like soiling — looks exactly like a behaviour problem, it gets missed constantly.
This guide explains the withholding cycle, how to spot constipation, and what to do about it.
An important note. Constipation is a medical topic, and this article is general education, not medical advice. Constipation during potty training should be discussed with your paediatrician or healthcare provider — they can assess your child, rule out other causes, and guide management. Seek prompt medical advice for significant blood in the stool, severe pain, vomiting, or weight loss. For the child-centred potty training approach overall, see our pillar guide, The Truth About 3-Day Potty Training.
The withholding cycle
To understand why constipation wrecks potty training, you have to understand the cycle that drives it.
| Stage in the cycle | What happens |
|---|---|
| One hard, uncomfortable poop | The child feels pain and concludes: pooping hurts, so I won’t do it |
| Holding it in | Stool sits in the colon, loses water, and becomes harder, larger, and drier |
| The next poop | It’s more painful — which deepens the fear and drives more holding |
| The cycle runs on | The stretched rectum becomes less sensitive, so the child stops feeling the urge, and softer stool leaks around the hard mass as overflow soiling |
It usually starts with one hard, uncomfortable poop. A child feels that pain — and a small child draws a very logical conclusion: pooping hurts, so I won’t do it. So they hold it in.
But holding it in is exactly the wrong move, because of what happens next. Stool that sits in the colon has more water absorbed out of it, so it becomes harder, larger, and drier. The next poop is therefore more painful — which deepens the fear, which drives more holding. Round and round.
Left to run, the cycle has a further twist. A rectum that’s constantly stretched by held stool becomes less sensitive — so the child genuinely stops feeling the urge. And softer stool can leak around the hard mass, producing soiling that looks like careless accidents or even diarrhea but is actually overflow from constipation.
This is why constipation is so often missed: the child who “won’t poop” and the child who’s “having accidents” can be the same constipated child, at different points in the same cycle.
Why potty training so often triggers it
Constipation and potty training are linked for specific reasons:
- Potty training is often the first time a child consciously holds their poop — because they don’t want to stop playing, don’t want to use an unfamiliar toilet, or feel pressured.
- The stress and pressure of training can itself promote holding.
- Children sometimes hold simply because the toileting setup is uncomfortable — perched on a big toilet, feet dangling, unable to relax.
- Dietary changes that sometimes accompany this age can play a part.
In other words, the very situation of potty training creates the opening for the cycle to start.
The signs of constipation
Catching it early matters. Look for:
- Infrequent bowel movements — fewer than your child’s normal pattern, or several days apart
- Hard, pebbly stools, or unusually large or wide stools — sometimes “the size of an adult’s”
- Straining, pain, or distress when pooping
- Small streaks of blood on the stool or the wipe, from a hard stool
- Tummy aches and sometimes a reduced appetite
- Withholding behaviours — and these are easy to mistake for trying to go: going up on tiptoes, stiffening the legs, crossing the legs, rocking, clenching, hiding in a corner, or gripping furniture. A child doing this is usually holding it in, not pushing it out.
- Soiling or leaking in the underwear — the counterintuitive one. Recurrent “accidents,” skid marks, or what looks like diarrhea can all be overflow around backed-up stool.
If several of these are present, constipation is very likely part of the picture.
Why you can’t potty train through it
Here is the key point for potty training specifically: you cannot successfully potty train a constipated child until the constipation is addressed.
As long as poops are hard and painful, a child’s fear is rational, and no chart, reward, or encouragement will out-argue it. As long as the rectum is stretched and overflowing, “accidents” will continue no matter how ready the child is. The constipation has to be treated as the priority — first, or at least alongside — and it’s usually right to ease the pressure on potty training itself while you do.
What to do
Start with your healthcare provider. This is the medical-adjacent part of potty training, and it’s worth a proper conversation. Your provider can confirm constipation, rule out other causes, and — importantly — guide treatment. Childhood constipation, especially once the cycle is established, often needs more than diet alone to break.
Follow their guidance on treatment. Providers commonly recommend a combination of dietary changes and, in many cases, a stool softener to keep poops soft and painless while the cycle is broken and the child’s fear unlearns itself. What to use and how much is a clinical decision — follow your provider’s instructions, and don’t start or stop medication on your own.
Support soft stools with food and fluids. Alongside medical guidance: plenty of water, and fibre from fruits, vegetables, and whole grains. Some fruits are particularly helpful for stool softness — your provider can suggest specifics.
Fix the toileting position. A footstool so the knees come up above the hips puts the body in a squat-like position that physically helps it relax and release. Use a child-sized seat insert so your child feels stable, not precarious.
Build in relaxed, unhurried sits. A calm few minutes on the potty after meals — when the body is naturally primed to go — with no pressure to perform, helps. Books and company are fine. Forcing is not.
Take the pressure off potty training. While you address constipation, lower the stakes. A more relaxed, low-pressure approach removes one of the triggers for holding.
Be patient. Breaking an established withholding cycle takes time — often weeks, sometimes longer — because the child has to relearn that pooping is safe and painless. Consistency over weeks is what does it.
When to seek medical advice promptly
Beyond the general recommendation to involve your provider: seek medical advice promptly for significant blood in the stool, severe abdominal pain, vomiting, weight loss, constipation in a very young infant, or constipation that isn’t improving despite treatment. These warrant a closer look.
A note from me
In our potty email series, we call constipation “the hidden variable,” and I mean it. When a family tells me potty training has completely stalled — refusal, accidents, a child in real distress — constipation is the first thing I ask about, and it is the answer far more often than parents expect. The reframe that helps most is this: a constipated child who won’t poop is not being difficult. They are being logical — pooping has hurt, so they’ve stopped. Make pooping soft and painless again, with your provider’s help, and the logic reverses on its own.
What to do this week
Look honestly at your child’s poops and behaviour against the signs above. If constipation looks likely — hard stools, straining, withholding postures, or unexplained soiling — make two moves: book a conversation with your healthcare provider, and put a footstool under your child’s feet today. Constipation is common, treatable, and very often the thing standing between your child and potty training success.
The Canadian Parent’s Potty Readiness Checklist
the developmental signs behind potty training that works, and the child-centred, low-pressure approach that helps prevent withholding.
Get the free guide →Frequently asked questions
Can constipation cause potty training problems?
Yes — it’s the most common hidden cause. Constipation drives poop refusal, accidents, soiling, and regression. Because backed-up stool can leak and look like careless accidents, constipation is frequently mistaken for a behaviour problem.
What is the withholding cycle?
A child has one hard, painful poop, concludes that pooping hurts, and holds it in. Held stool becomes harder and larger, so the next poop hurts more — deepening the fear and the holding. It’s a self-feeding cycle that needs to be deliberately broken.
What are the signs of constipation in a potty training child?
Infrequent, hard, pebbly or very large stools; straining or pain; small blood streaks; tummy aches; withholding behaviours like going on tiptoes, stiffening, crossing the legs, or hiding; and — counterintuitively — soiling or leaking that looks like accidents or diarrhea.
Can I potty train a child who is constipated?
Not successfully, until the constipation is addressed. While poops are hard and painful, a child’s fear is rational, and accidents from overflow leakage will continue. Treat the constipation first or alongside, with your provider’s guidance, and ease the pressure on training.
When should I see a doctor about my child’s constipation?
Constipation during potty training is worth discussing with your healthcare provider generally. Seek prompt medical advice for significant blood in the stool, severe pain, vomiting, weight loss, or constipation that isn’t improving with treatment.
Sources
- Canadian Paediatric Society (Caring for Kids, 2023). Toilet learning. caringforkids.cps.ca
- Canadian Paediatric Society (Caring for Kids, 2018). Healthy bowel habits. caringforkids.cps.ca
- Rowan-Legg A / Canadian Paediatric Society (2011). Managing functional constipation in children. Paediatr Child Health. PMC
- Tabbers MM, et al. / ESPGHAN & NASPGHAN (2014). Evaluation and treatment of functional constipation in infants and children. JPGN 58:258-274. naspghan.org
- American Academy of Pediatrics (HealthyChildren.org, 2026). Soiling (encopresis). healthychildren.org
- American Academy of Pediatrics (HealthyChildren.org, 2024). Constipation. healthychildren.org
This is general education, not medical advice. Persistent constipation needs a plan from your child’s doctor.
About Milos
Milos is the founder of Sleep Ready and Life Safe, a certified paediatric sleep and potty consultant through the Institute of Pediatric Sleep and Parenting (four specializations), a certified First Aid and CPR instructor for over a decade, and the dad of twins. Sleep Ready serves Canadian families virtually across Canada and in-home across most of Ontario.
Rested child. Prepared parent. That’s Sleep Ready.