W.D.
Hi E.~
My sons haven't ever had severe diaper rash, but when their bottoms start to get a bit red and irritated, I use cornstarch in the irritated areas. You may also want to use a wet paper towel or wash cloth instead of the wipes. When the rash has started, sometimes the wipes can make it even worse. Be liberal with the cornstarch at every diaper change. Hope it helps!
Take care,
W.