Hi
@H Nazz and welcome to the forums.
I am sorry your daughter has this diagnosis. Though I can fairly confidently say that things will get easier the combination of the new diagnosis with such a young child must make things very difficult for you right now,
I don't really have an answer for you, other than that illness can cause higher blood sugars so am not sure whether the diarrhoa is cause or effect here (or unrelated).
Are you in close contact with your diabetic team about this issue? They are really in the best position to help you and with a 5 year old child I wouldn't hesitate to contact them as frequently as you need to.
Lots of virtual hugs.