It's possible that the soap isn't the problem at all. If you have a urinary tract infection, it'll burn when you pee. See, I would think it'd be kinda difficult to get soap INTO the urethra, but... Last thing -- are you sexually active? If you are, there's a chance you have gonorrhea, but I'd guess you don't. You'd know.
PhD student - Organic Chemistry
I don't read an entire thread before I respond; I try to answer the question quickly and concisely.