My kids go to school/nursery with spare clothes, you would be surprised by how many kids don't. We don't have many spare staff and often sacrifice 1:1 support so someone can run around school finding spare clothes, when found they are rarely returned. Most often staff buy spare pants and socks, but it isn't anyone but the parents job to do this. Perhaps all children should come with spare clothes because too often we get grief from parents for having to use lost property clothes, not clean or too big/small.
Due to covid all lost property has been cleared out, part of preparing our school for a hub. So we would have no spares to loan to a child just now.
Whilst I wouldn't leave a child sitting alone upset in a toilet, if our policy was hands off then i would talk the child through cleaning themselves ensuring they had what I could provide to help them, we don't have wipes only toilet paper.
However we have to be so careful before putting hands on, especially if not the normal teacher. Do you know if the child has suffered abuse? If the school policy is no personal care, then you do personal care you can't say I didn't know about the abuse as you didn't need to know. That could be you out a job and struck off from your registration body. Sonbefore making a complaint ask questions and find out what the policy is, ask if someone could have verbally supported your child to clean themselves, had you provided spare clothes, if not could they have loaned them some.
Whilst we look at this situation and think it sounds insane, who would treat a child like that, please remember there are reasons behind all policies, we may not always agree with them but find out why things were done before suggesting others should just go ahead and do something like personal care. To the poster who said they did juat this as a volunteer 🙄 you broke every safeguarding guide. You should never have been left alone with kids let alone in any situation of personal care. The school could have been in massive trouble had a parent taken that further.