3 Day Old Piglets with Diarrhea

Our Sow had her litter of 12 3 days ago yesterday we noticed they were looking skinny today they all have diarrhea and have lost 4, we have taken them off their mum this afternoon and have started self feeding them with Milk replacement and home made electrolytes and have them under the heat lamp.
We live very rural so a bit difficult to get the vet out
Ive read up and it sounds like Scours would anyone have advise to give on treatment and prevention and how often i should be feeding them electrolytes and milk replacement

Any advice would be greatly appreciated

Thanks