infant with rash near butthole

My LO rashes near butt hole area still cannot fully recover. Coming to 2 months already. Some days looks good and some days the redness is there. Is it because it's girl, hence it's more sensitive? Mustela didn't worked for her Purple desitin too strong for her. Cerandan was recommended by PD when we brought her in mid Jan. It got better but slight redness still there. Using Jo Lauren balm. It works well for neck and armpit rash but not her rash near her butt hole. What other diaper cream or balm would u suggest? PS: butt wash after poo, diaper brand from merries to plantinum Huggies and frequent diaper change. TIA!