Help - Daughter won't poo in potty or toilet!!

My DD, aged 2y8m, started potty training at the end of July when DS had broken up from school. She’s been pretty good with wees, and most of them end up in the potty or toilet just fine! Poos are another matter though; she just won’t do them anywhere but her pull-up at nap or bed time.

She knows where they should go, and if you ask her where we do our poos she will say ‘potty or toilet’, she is not afraid of the potty or toilet as she sits on both happily to do wees, she isn’t constipated and doesn’t seem to have any pain doing poos. She knows when she needs a poo, she’ll tell me, we’ll sit on the potty or toilet (her choice of either), read books, run the taps, sing songs, blow bubbles for up to half an hour, but there will be nothing in the potty/toilet, or just wee.

Then the next time I put her in a pull-up she will have pood in it within 5 minutes of putting her in her cot-bed. One thing I have noticed is that she seems to poo when she’s on all 4s, and sometimes crawling backwards!

Does anyone have any tips on how to encourage her to poo on the potty or toilet? I’ve tried bribery and asking her if she’s worried or frightened about wearing a nappy, and even having her in a pull-up but trying to get her to sit on the potty or toilet, but to no avail. I don’t want to worry or make her anxious; the last thing I want is for her to start with-holding poo and giving herself bigger problems.

Thanks in advance for any advice XXX