I've had hemorrhoid surgery twice, the second surgery was years before I discovered parasites. Nowadays, anytime I have rectal itching I ramp up on parasite herbs and I always pass worms just about the time the itching stops.
One round of parasite herbs wont kill them completely unless you are very healthy. The longer you have had parasites and heavy metals, the less likely you are to be healthy regardless of how you feel at the moment.