If you've treated the diaper rash at home for 3 to 4 days and the diaper rash hasn't cleared up or seems to get worse then that's when you should take your baby or toddler to the doctor for his/her diaper rash.
Your doctor can prescribe a stronger ointment that can help clear up the diaper rash.
If you haven't tried it already you might want to give your toddler or baby an oatmeal bath because oatmeal will usually clear up diaper rash naturally as long as the diaper rash isn't too severe.
Be sure to change your babies diaper often to prevent diaper rash, check your baby or toddler for a wet diaper at least every 2 hours and change when needed.
If your baby or toddler poops in their diaper then the diaper will need changed right after they poop to prevent the bacteria in the poop from causing diaper rash.