I'm experiencing this strange pain in my bottom when I sit for a long time. It really burns, but interestingly, when I stand, run, or sleep, the pain goes away. I don't feel any pain or see blood when I go to the toilet, although I am dealing with a little constipation. There's no blood or pus in my stool either. Some people are telling me it might be piles, others say it could be fissures or maybe even a fistula. I'm really confused and would appreciate some guidance on what this might be.