Thank you for your query,
Frequent little bit loose stools are normal in newborns and after feed they pass stool due to gastrocolic reflex which is normal in infants.
is a good sign of adequate feeds and proper hydration.
You continue exclusive breastfeeding
If the loose motions still present you can give lactobacillus
probiotic after doctor consultation.
For the diaper rash, clean the area gently, allow it to get dry and apply the diaper rash cream
Hope I have answered your query.