DS won't poo on toilet

[twinkletoes1988]

My DS in 4 next week. I think he has a form of autism, he cannot stand change to routine.
He's fully potty trained during the day I can't remember the last time he had an accident. But he waits until the evening when he has a nappy on to poo. He will not poo on the toilet or potty, to the point he would make himself badly constipated and in pain rather than use the toilet.
What can we do?

Said before but I’ll say it again here. It’s more common than you think.

I have a friend who has a similar problem to this. She has a three year old DD who is nearly 4 and in her last year of nursery.

She is tall for her age and looks older. She is also articulate and speaks very clearly.

I had a socially distanced meet in a cafe recently and she brought her DD with her.

Her DD actually ANNOUNCED that she was going to poo and went off into a corner to squat down and poo (presumably in a nappy or pull-up). It was a bizarre sight to see, I can tell you.

She then returned to our table and (in her
most confident and grown-up sounding voice) told my (now embarrassed-looking) friend that she needed changing!

My friend told me that her DD had no problem with wees and is even dry at night but will just not poo on a potty or toilet and she has yet to find a solution.

All I could muster was to suggest a GP visit. I asked her if she had spoken to her DD about it but her DD refuses to discuss it, so she’s not getting anywhere.

My DD’s and I all had wee issues when small, probably attributable to black current juice, but potty refusal for poos is a new one.

I will refer my friend to these threads in case anything here helps.

I suppose the point I’m trying to make is that it’s more common that you would think.

You might want to try this method with him.

Let him have a nappy, but only if he has it on and sits on the potty. Once (if) he's agreed to poo in the potty but with a nappy fully on, let him have a couple of weeks doing this and then do the same but put the nappy on more loosely.

The aim is that over several weeks you gradually make the nappy more loose until you just lie the nappy in the potty and he poos onto it, then eventually he just pops in the potty or toilet.

If he's very reluctant though, and you do suspect ASD it might be worth speaking to your GP and asking for a referral fir a proper assessment, especially if he's starting school in September