Teenage crippling stomach cramps - inflammatory response?

[Chrysanthamummy]

My teenage daughter had terrible cramping in her stomach a couple of weeks ago. We were directed to A&E by 111 where they did lots of tests but found nothing but some blood in urine. The pain receded and we came home and she was very sick overnight. Now she’s fine.
I’m just wondering is anyone else has seen this in their children as I’ve since heard of 4 other children with exactly the same symptoms. I’ve also read that similar things can happen (normally alongside other symptoms, rash, temp etc) 4-6 weeks after having Covid-19. She had a terrible ‘bronchial infection’ (according to the Dr) just before lockdown. She’s never been tested for Covid.