How do you phase a reward chart out with out them regressing

[cedar12]

My dd is 4 started having accident again after being constipated. Have used a reward chart before with her its quite a on going problem. She is fine for ages but is now wetting once a day usually when she is playing in the garden or with friends. My hv dosent think a sticker chart will work in the long term as she keeps on reverting back. But she does respond well to them in the short term but I would like to know how other people have phased them out.

Had this prob when my dd was 2 half. We got over it in a silly way. One thing i do know is it may be connected with her bowel. Friend of mine has similar prob but on much bigger scale. hospital told her if her bowel is full it can press on bladder and she may not actually have much control over wee at that time. My advice is to just change her without fuss and i know it will sort itself out. Bigger deal you make of it the worse it will become.