Reaction to Rice Milk but fine with Rice?

DD1 who has just turned 4 came down with something on Easter - fever and vomiting (about 6 times overnight) - it freaked us out a little since it is the first time she has been sick sick (prior to this she has had a couple of basic colds) but seemed to just be that 24hr virus that was apparently doing the rounds plus all of the chocolate she inhaled through the day wouldn't have helped.

The next day she was a little bit less energetic but no more vomiting, she spent the day quite lazily mostly resting on the couch (very unlike her as we usually are a TV free zone).

The morning after that she seemed fine but had a drink of cow's milk for breakfast and proceeded to throw up which we figured was just because her immune system was down a little and her gut bacteria might have been compromised (although no medicine was given/taken) so decided to hold off on milk for a while. She was fine the rest of that day (yesterday) although had a nap which she doesn't usually do.

That night before bed she had a small drink of rice milk (first time having) and woke up twice to explosive diarrhea, this morning she had a hive like rash and continued loose stools.

We took her to the doctor this morning (although couldn't get into our usual one so went to a walk in clinic) who said it was a reaction, probably to the rice milk and unrelated to the original vomiting situation but didn't seem to answer the question of why she was reacting to rice milk when she has had rice (brown) and rice noodles many times before with no issue. The rice milk was the only different (being sick she has only been having toast and fruit) thing she has had recently so it makes sense for it to be that but what should we do now?

He didn't even really say to avoid it in the future so we want to follow it up with our usual doctor but I don't want to completely overreact as sickness is a foreign concept for us so far so I'm not clear on what is normal but feel we should be investigating this further? I have tried googling but can't seem to find whether there is something particular in rice milk but not rice that could be the issue, does anyone know? The ingredients listed are filtered water, organic brown rice, organic sunflower oil, plant calcium and sea salt so nothing jumps out at me. She has never had a reaction to anything before and has a fairly varied diet.

Confuuuuuuused.

Could it simply be that her tummy was still really sensitive to anything and everything and rice milk being a liquid form and digested more quickly than rice per se could have caused the reaction?? Could you just cut out all milk type products (dairy or otherwise) for a week or so and then slowly re-introduce??? Hive sounds weird though, could have been a reaction built up over time though. Not much help sorry, hope you work out what it is oxox

I think it could well be a progression of the original illness, not a reaction to rice milk (or anything else) necessarily.
Wait till she's definitely well, and then see how you're going with foods.

I definitely put the cow's milk down to that because of how illness can affect tolerances of some food (dairy in particular) but didn't know if that could include rice milk (which we got because of the whole dairy business but obviously will just stick with water which is all she really has except for milk with dinner). It really just doesn't make sense she would suddenly be having a reaction to rice milk, I mean we don't have rice often but often enough to know she has been fine with it for four years and with it being so close to the vomiting business it does seem like it should be connected in some way.

The hives have gone now so were only kicking around for half a day, still loose stools. Seems more tired than usual but in good spirits and still actively playing and stuff, TV back off today. Just odd how she was super vomity one night then fine for a day then a single vomit then fine then diarrhea lol such an odd progression. Hopefully we are past it all soon, kinda realising how lucky I was to avoid this stuff till now, draining to be so actively concerned plus you know, cleaning vomit and such!

Thinking about it, I should just express off some breastmilk for her to have... reline her stomach and all that (I would just let her feed but she weaned 9 months ago and has definitely lost the knack lol).

If it were me, I'd assume it was nothing to do with the food and everything to do with the illness. I've had bugs like that, that seem to come and go. :dunno:
Some breastmilk for her gut wouldn't 'hurt at any rate :)