Hello there, am having the rectum pain since yesterday, and really terrible/untolerable yesterday. it still there, i don, t understand y is it, and s?

Hemorrhoid/Abscess: Was it sudden onset with continuous pain? Or was it gradual onset with fevers and chills? The first is a thrombosed external hemorroid, the second an abscess. Those are the most likely, although it could be something else. Either way i think you should be evaluated by your doctor.

Rectal abscess ?: May be you are developing a rectal abscess, it could be the reason for sudden pain, go to your doctor for examination and possible drainage of abscess.