Unusual discharge????

Normally when I go to wipe after using the toilet, whether i use toilet paper or a washcloth, it always comes back with an odd white substance on it. It seems to pill up, like wiping away dead skin after exfoliating, but it's a bright white. It seems to collect in the folds of my vulva. It's really hard to clean it all out, because when i try to wipe it away, it just clumps up and won't stick to toilet paper. What is it and how can I make it go away?