Cuts on my baby anal

Hi everyone Currently my baby is 26 days old and her backside have cut and is causing her discomfort.I am applying diaper rash cream on that area but is not working even i am cleaning that area with lukewarm water with cotton ball after that applying diaper rash cream on that area and keeping the area dry and keeping it open but still nothing is helping me out. I bring her see Dr they prescirbed me Baneocin powder and Desitin cream. I am attaching the pic of that area please have a look and help me to advise what should i do. Thank you Waiting for your quick response#pleasehelp #firstbaby