Does anyone have any good suggestions to help cure a bad diaper rash that won’t go away & keeps coming back for 2 weeks??

Thanks for the support, I used corn starch & it went away.. The diapers have been the same brand for over a year & I found out that every time she visited her father (I am fostering my niece & nephew) he fed her citrus that does cause her booty to break out! He knew & did it despite me telling him not to feed her citrus anything🤦‍♀️ & since she sees him every other day, that’s why it would clear up & then come back every time she went poo..