5 year old wetting herself on purpose, what do I do?

[Majesty]

Just after advice because I’m at my wits end. 5 year old has been potty trained since she was 2. Dry, day and night for years. Except she goes through phases where she wets herself because she can’t be bothered to go to the toilet. If asked, she will literally say she didn’t want to stop what she was doing and go to the toilet so just wets herself instead. I’ve tried ignoring it, punishing her, leaving her in her damp clothes (for a few minutes so she gets the wet feeling), taking her to the toilet hourly. I’ve threatened her with nappies at school, I’ve bought her special pants that will be thrown away if she wets them. We’ve done sticker charts to stay dry, treats out etc. Ive switched her clothes to make it easier to pull them up/down. Nothing works. She doesn’t care about having wet pants, she just wants to keep playing. When she wets her pants we stop what we are doing and go in so it doesn’t even work!
I've had her checked for urine infections and nothing. I googled and sexual abuse came up, it’s definitely not that. I just don’t know what to do! It’s not all the time, maybe for 5/6 days and then it stops for a month or two, and then she starts again. She’s an intelligent child with good communication skills. Is more than capable of going to the toilet by herself. What can I do?

thanks everyone. I’ll have a look at ERIC. I’m pretty sure it’s not ASD or ADHD because older sibling has both so I’ve spent half my life researching all the different aspects and she has no other signs of it. I’ve started tracking her poops (so glamorous!) to see if it changes depending on her pooping as it does seem to be phases. For those who’ve suggested it, I always make her clean and change and will usually go with her but don’t help as she’s more than capable :)

I picked up an infection that caused an irritation when I was about 8.
Every time I pooed, I wanted to wee constantly for about an hour afterwards.
Would wee like 5 or 6 times but still got the 'gotta pee' feelings.
Think it lasted a couple of months?
Completely separately at a different time one of my half sisters had a similar thing. I was a foster family and we couldn't have picked up an infection from same place.
Could it be similar to that?

Both my boys did this! Younger one (who is now 9) will still very occasionally wet himself when playing computer games, instead of taking a break to use the toilet! Mostly though he's grown out of it. Older DS grew out of it a bit quicker!

I generally dealt with it by not making a fuss. Helped them get changed, talked about using the toilet next time and move on. Is not a big deal and don't make it one or it will become a huge problem.