Hello , good evening.
Thanks for writing to us.
According to the symptoms you have mentioned, i feel that your baby might be having a simple lactose intolerance
i.e transient intolerance towards lactose present in either mothers milk or cows milk.
I suggest you to get a stool routine and stool reducing substance test done and be back with the reports, analysing the reports , we can guide you properly.
For the rashes , candid
ointment will not be enough.
Keep the area dry and you can apply rashfree ointment.
Kindly review with the reports.
Thank you, regards.