i think I need a second bout

Almost certainly.

Most of these, you kill off the adults with whatever stuff you take to get rid of them, but the eggs in your system are still around. An *essential* part of treatment is to hit them with a second dose after the eggs have hatched but before the critters get to reproduce. For most of them, I think that's two weeks.

OTOH, I also remember the NewScientist article a little while back where people with IBS were deliberately given parasitic worms that live in pigs. The worms couldn't survive long-term in humans, but did for a bit. Most of these people, their IBS cleared up. A major current hypothesis is that IBS and other similar grief is caused by a lack of internal parasites, so your body's defence mechanisms get over-sensitive with nothing to do.

Graham.