My daughter got her first diaper rash at 4 mos. We were using Boudreaux's Natural Butt Paste and are STILL happy with it. However, to get rid of the diaper rash we used BAG BALM. For two days we washed her bottom off with a warm wash clothes at every diaper change and used ONLY the BAG BALM. It COMPLETELY cleared up. We returned to using Beaudreaux's once it was gone and it hasn't come back.
The stuff is awesome! I bought it for around $8 at CVS. It comes in a cute green old fashioned tin with tiny red roses on it. It's original use was for chapped cow's utters but obviously it works wonders on diaper rash amongst other things.
TRY THE 'BAG BALM'...IT WORKS!