I'm glad you are getting this taken care of quickly! Unfortunately, it will only get bigger! The amount of pain may relate to the location of the abscess and whether it is pushing up against something. But I too am wondering if it hasn't formed a fistula and is draining somewhere. I've had abscesses hurt and then not hurt because they drained alittle, and then they filled up again and hurt -- up, down, etc. I hope your surgeons are experienced with CD and take care of it for you!! Remember several sitz baths a day (in the tub) and take plenty of time off so it can heal completely! I am almost through recovering from a per-rectal abscess so I know what you are going through!!
Take care and let us know how it goes!!