What kind of rash do you think this is?

It’s accompanied with diarrhea. She doesn’t have a fever or anything like that, but the rash has been on and off for like two months. I took her to the doctors two months ago and they told me not to worry about it, just put destin on it. I’ve been doing that religiously, but it’s come back even worse. She’s only has the diarrhea for three days.

I’ve been actually supplementing with formula for the past couple months and only just recently switched her to formula exclusively, like a week ago. I’m wondering if she is having some sort of reaction to it. I don’t know though because I have been supplementing with formula for a couple months, but she has had that rash for a couple months though. maybe it’s something else? Could it be ring worm? Im taking her to the doctors tonight to find out. What does everyone think?