My 12 year old daughter is itching her bum a lot and it is bleeding and the pain is stinging why? should i take her to the doc or just wait it off

If : If she is scratching to the point of bleeding, you should take her in to see her doctor. There are a variety of things that could cause her symptoms such as pinworms, peri-anal strep infection, anal fissure or tear, or skin irritation from poor hygiene. In the meantime, sitz baths with 2 tablespoons of baking soda may help alleviate some of the itching and pain. Good luck!