I was also going to say that sudocreme and metanium and bepanthem can really sting.
I use waitrose baby bottom butter and have since she was born. th only time she has nappy rash is when she is teething, has tummy upset - so lots of diarrhea and when she has thrush.
Are you sure it's not thrush? babies both boys and girls can get thrush, just due to the environment that thrush likes to be in... moist dark warm places!
I also use a great cream by "earth friendly baby" which 'active' ingredient is Red Clover. I can put it on at night, and her rash is gone by morning, often. Unless very bad, or bleeding. then it takes a few applications. THat said, i think it also stings when it goes on if bleeding...
SO, if bleeding, I use a cream by Welda - Calenduar Nappy creme. Which out of all of them, is the most useful as non sting, & does heal fairly fast.
If you don't want to get all 3, of course, then go for the red clover one or the calenduar one. both just as good, as long as not broken skin and bleeding.
HTH