Short answer: Constipation is common in children and often becomes a cycle: a painful poo leads to holding on, which makes the next poo harder and more painful. Signs include fewer than three poos a week, hard or pellet-like poo, straining, tummy ache and, in children over one, soiling from runny poo leaking around a hard blockage. See a GP: children who eat solids are often prescribed laxatives, sometimes for months, alongside fluids, fibre and a calm toilet routine. Stopping treatment too early is a common reason it comes back.
Your toddler is standing on tiptoes behind the sofa, red-faced, fists clenched. It looks like pushing. It's usually the opposite: holding on.
How the cycle starts
One hard, painful poo is enough. Your child remembers the pain and tries to hold on next time. The longer poo stays in the bowel, the more water is absorbed and the harder it gets — so the next one hurts more. Over time, the bowel can stretch and the urge to go becomes weaker.
That's when a confusing sign can appear: runny poo leaking around the hard blockage into pants. It can look like diarrhoea, but it's often constipation with “overflow soiling”. Your child isn't doing it on purpose.
A child with soiled pants is almost never lazy or naughty. It's usually a child with a full bowel who can't feel it properly any more.
Signs of constipation
- fewer than three poos in the last week;
- hard, large, or small pellet-like poos;
- straining or pain when pooing;
- holding behaviours: crossing legs, standing on tiptoes, hiding;
- tummy ache that eases after a poo, or poor appetite;
- soiling in a child who was already toilet trained;
- a little blood on the paper from a small tear.
Common causes
Not eating enough fibre-rich foods, not drinking enough, changes in routine or diet, feeling pressured or interrupted during potty training, or not wanting to poo in certain places, such as nursery or school.
Treatment
If you think your child is constipated, take them to a GP — ideally before it becomes a long-standing problem. For children eating solid food, laxatives are often recommended alongside diet and routine changes. UK guidance (NICE) recommends a macrogol laxative as first-line treatment for most children.
- Treatment may take several months to work. Keep going as advised.
- Laxatives can make soiling worse at first, before it gets better.
- Your GP may advise continuing laxatives for a while after things improve, so poo stays soft and your child loses their fear of pooing. Don't stop suddenly without advice.
What helps at home
- Plenty to drink: breastfed babies not on solids can have extra breastfeeds; formula-fed babies can have extra cooled boiled water between feeds; older children should drink regularly through the day.
- Fibre: a variety of fruit, vegetables, wholegrains and pulses.
- A regular toilet routine: sit on the potty or toilet after meals or before bed, and praise them whether or not they poo.
- Good position: feet flat on the floor or a step, so knees are higher than hips.
- Stay calm about accidents: no telling off or shaming, which makes holding on worse.
- Get moving: active play every day helps the bowel too.
- Ask about worries: some children avoid pooing at nursery or school.
When to get help quickly
See a GP promptly if your baby is constipated in the first weeks of life, or if constipation comes with vomiting, a swollen tummy, blood in poo, weight loss or poor growth, or severe tummy pain. Call NHS 111 (or your local equivalent) if you're worried, and 999 (UK), 911 (US) or 112 (EU) for severe pain with a very unwell child.
Related reading
Toilet training without pressure: Potty Training without Stress (PDF, English) covers toilet training at your child's pace, without struggle or panic.
Sources
- NHS — Constipation in children.
- NHS — Soiling (child pooing their pants).
- NICE — Constipation in children and young people (CG99).
- Alder Hey Children's NHS Foundation Trust — Constipation.
Written by the Bloom Guides editorial team. Last updated: 20 October 2026. General information only — not a substitute for advice from your GP or health visitor.