3 year old struggles with poo - will do it only in nappy

[VS2022]

hello
I know this is a very common topic… my 3 year old son has been potty trained for wees since he was 2.5 and has very few wee accidents… Maybe once a week if he’s too busy playing at his nursery. his development is totally fine otherwise too and he’s a bit chatterbox.

We just cannot get him to do a poo in the potty or toilet. He’s on movicol but he still refuses the potty and basically will only poo after nursery requesting a nappy or before bedtime (which makes bedtime painful). He does get constipated a lot and we think this is what caused this in the first place. We’ve tried bribes, asking him to sit on the toilet with a nappy… we just want him to get used to the idea of doing it in the toilet and he refuses and usually will only insist on his room…
sorry for rambling but it’s stressing us both out a lot and nursery have tried to help but he refuses there…
any suggestions from others in this situation?
thank you!

Following as we have the exact same problem!

Following for the same problem here!

Hello! We have found ERIC very useful for advice on this. Our child turned three earlier this month and despite being dry since November, will only really poo in a nappy. Any poo that has happened on the potty or toilet has been a ‘happy accident’. I would suggest the first step is to insist that poos happen in the bathroom only. So he can tell you that he needs to go, the toilet is offered every time but if he insists on a nappy, he has to go to the bathroom and do it there. This is the stage we are currently at! Very happy to provide more context if helpful, but here is the ERIC advice: eric.org.uk/children-who-will-only-poo-in-a-nappy-and-other-toilet-avoiders/

Updating here with a couple of things we’ve had some success with.
A family toilet seat. So we now have one with a built in, fold down child’s seat that means we don’t need to use a separate child’s seat like we had been doing so far. Our daughter felt that was now too babyish for her and wanted to sit on the ‘adult’ toilet seat, but couldn’t relax enough to go to the toilet because she had to hold on with her hands! The one we found is great, because it is almost exactly like the toilet seats they had at Legoland when we visited a few months ago, so we’ve called it the Legoland toilet seat and she is happy to use this.
A blowing toy. We’d tried blowing bubbles but the novelty wore off quickly. Apparently blowing is helpful to anyone trying to go to the toilet as it helps relax the muscles (slightly annoying noise but we were way past caring about that); only she gets to use it and only when sitting on the toilet. At all other times it’s shut in the bathroom cupboard.
Worth mentioning that we are not yet out of the woods but progress has been huge. We started potty training in November 2025 and it’s taken until now to get to this point. Happy to discuss privately with anyone who wishes to!

Second the ERIC website.

helped us through the same issue and we’re ten years down the line!