My friend smells really bad

So one of my friends smell really really bad, like urine and like something is wrong in her downstairs department. Something might actually be wrong physically with her, but it’s been months, and it makes me not want to be near her. I want to tell her to go to the doctor or maybe clean herself more thoroughly but that seems too harsh. And also, it’s really strong so she must have noticed it herself too right? How do I tell her that she smells bad and should do something about it?