I picked up Blastocystis Hominis and Dientamoeba Fragilis on an extended kayaking trip in Canada. That was 3 years ago. I'm still suffering, and am about to start the triple drug cocktail plus doxycycline (Jackie's suggestion - badbugs.org).
I want to share what has helped reduce the numbers of parasites for me:
Diet - Completely eliminate the following in order worst to not so bad. This is so you don't feed the parasites and increase their population:
Probiotics - Supplements, yoghurt, saurkraut
Sugars - Sugar, honey, cane juice, fruit, etc.
Corn (really watch those labels, it's in everything)
Grains including whole grains and rice
Tofu - too much calcium and they like calcium
Do not experiment with drugs and herbal products unless you're sure they'll work. These parasites will die off for the first 4 or 5 days and will then develop a resistance. You must rotate through a series of treatments only taking each for 4 or 5 days or take something really strong like maybe the triple cocktail.
Some of them I could only get through a doctor of Traditional Chinese Medicine.
I have found that several times I've thought for sure the parasites were gone, only to have them reappear after about 3 months. I will take lots of probiotics, especially saurkraut when I've finished the cocktail so that when the doctor tests me, it will be obvious whether the parasites are gone or not. As well, if they are gone, it will rebuild my digestive flora.
I've gone to great effort to get the cocktail: setting up a mailbox in the US and ordering them from medsmex.com, then smuggling them into Canada. I'm pretty desperate because the above was not a cure for me, it only helps reduce the symptoms. I'm nervous about taking these drugs because otherwise I was so healthy and health conscious, but I want my life back. I'll try to check back in here when I'm done.