Help with poorly two year old

[FloatyFlo]

My daughter came down with a virus a week and a half ago. Full of cold and temperature. This began to clear up after a week. She's still a bit snotty and got a cough but is otherwise well.
She lived on cheese, yoghurt, milk, ham and cereal, as this was pretty much all she'd eat. Odd few grapes in there too.

But now she has barely eaten for three days. She had cup of milk two days ago and it came straight back up. She had a milkshake yesterday as this was the only fluid she'd accept. That came straight back up too.

I'm basically wondering if the dairy diet has caused some tummy upset and constipation. She has had one bowel movement in three days.

Pharmacist gave us lactulose. But I'm not sure if she's not pooing because she's not eating, or if she's not pooing because shes constipated (which then is leading to not eating).

Is she okay on lactulose with an empty stomach?

What do you think?

Just to clarify, we couldn't get in to see the GP today but can get an appointment Monday. Out of hours doctor is available over the weekend if needed. Just looking for some advice in the meantime.

Also, to add, any juice water or squash she has had and has stayed down. The tiny tiny nibbles of food she has had, has also stayed down. It's just the milk that hasn't so is it wise to cut the dairy?

If its only been 3 days since her last poo then i wouldnt worry about her being constipated. Theres not been much going in to come out! If you think shes straining to poo though or her poos look hard instead of soft, lactulose on an empty tummy will be fine. Its basically just sugar.

I'd prob avoid dairy for a few days, stick to juice and plain foods. Even if shes not eating much as long as shes drinking shell be ok for a few days. Affter a few days maybe try her with a small amounts at a time of milk again until she can keep it down.

Hope shes back to normal soon!

Some viruses can cause a temp lactose intolerance
Keep off dairy for while

Thank you for your reassuring replies. She actally pooed earlier. Tmi - but it was like a hard tennis ball so I imagine it has definitely be causing some bother. I will keep her off the dairy for now. She has been dreadful for drinking. Really bad. Point blank refusing to drink anything. Even her favourite squash or a sip of my lemonade has been refused. I've taken to bribing her with stickers to drink water. If that begins to fail I am seriously considering calpol-syringing it in!

Some people use ice lollies as a sneaky way to get fluids in to stubborn toddlers

That's a good idea thanks!