Toddler witholding poo

[MummaBear144]

Hi all in desperate need of help and advice.
My DD 2.9 has been holding her poo in for weeks, this resulted in a trip to our hospital last week. She was prescribed movicol and ended up managing 2 or 3 small poos a day for the next 3 days.

During these days she started using the potty and even pooped on the potty but in the past 2 days has started holding again.
She's had at least 2 urine accidents each day, is this related?
When i talk to her about it she says she's scared of poo and doesn't like it but I can't get any more out of her.

Her bum looks ok, no tears or soreness and we were also given magic cream to prevent any sores.

Ive even offered to put her nappy back on so she can go incase it was fear of going on the potty.
If anyone can offer any advice I'd really appreciate it, as my next step is to the gp in tears. What a stressful time!!