Suggest Treatment For Pain In The Anal Region

Hello, I have a weird pain in the anus area. It starts dull and then goes up the pelvis andd my internal female organs. Sometimes (rarely) the pain will go up to the belly and it will become tender to the touch and very tense (this happens couple times or once a year). One time because of this pain I was carried to the hospital because I was screaming from it. Now it s the same - I am laying down on my back and I feel weird sensation around my anus/rectum area. And then it becomes painful. They looked into my stomach - it s healthy, did the echoscopy of my internal organs - nothing out of the ordinary. BUt the pain is so intense, I cannot sit down. I ve had problems with hemmorhoids but I am taking medication (Posterisan) and it helped a lot. It never hurt to defecate or sit or anything and the pain isn t constant but it sucks. It feels like my rectum is on fire and it hurts to move on the side even... I don t know what it could be. they also took a sample for the bacteria, but didn t find anything. Told me that I literally look healthy. But what is this pain..? I am a 23 y.o. female