Wormwood tincture and/or activated charcoal (the later 4 hours away from supplements and/or meds) can help with giardia just in case you do have it. It tends to recur, so sometimes one has to do the treatment more than once, maybe several times.
The truth is you probably had parasites before you ever stepped on the plane to leave the states. If you go on a campaign to get rid of them, that is very likely to kill whatever you may have picked up overseas.
See link below for cayenne pepper challenge test to see if you have tapeworms, for example. Hulda Clark says everyone she ever lab tested had Tapeworms & everyone had other kinds of parasites as well.
What helped me in case any of it can help you: //www.curezone.org/forums/fm.asp?i=1522290#i