We've just had 2 rounds of D&V in our family, the second lot quite nasty and hit all of us; DS 2 yrs ended up being rehydrated in hospital. What suprised me most was the contradicting advice we were given from health professionals and these guidelines from NICE www.nice.org.uk/cg84 would have saved me a lot of bother had I known about them sooner!
Firstly, when to seek medical advice for little ones. Over phone was told by out-of-hours nurse that 2 yr old wouldn't be dehydrated yet despite repeated vomiting and diarrhoea. He was seen by GP anyway as had a croup-like cough but turned out he was dehydrated and the Dr who saw him sent him straight to hospital! This clinical guideline from NICE gives guidelines on 'red flags' suggesting dehydration or shock which parents can look out for.
We were also given lots of different advice about when to start milk and/or food again, and these guidelines are very clear on what & when.
Here's the link is for the parent/carer advice: guidance.nice.org.uk/CG84/PublicInfo/pdf/English.
Hope other people find it useful, there's lots of D&V around at the moment!
NICE has also published a guideline on feverish illness www.nice.org.uk/cg47 and the version for parents is here guidance.nice.org.uk/CG47/PublicInfo/pdf/English
NICE www.nice.org.uk publishes lots of guidance relating to child health, including food allergies, eczema, cancer, UTIs, bedwetting etc (just search 'children' to see them all) and I'd really recommend having a look if you are struggling to understand a health problem your child has or want to make sure they are receiving the best possible care.