I realize this thread is out of date, but it seems the most relevant location ... as it really helped me along the way.
Like many of you - after several years of increasing misery, I finally was tested for and diagnosed with blastocystis hominis & dientamoeba fragilis. I took the triple drug cocktail for 10 days (per my naturopath's instructions): secnidazole, furazolidone, and nitazoxanide.
Afterwards, I had about two weeks of blissful normalcy. After years of suffering, it starts to mess with you psychologically and just a short period of health is tremendously validating.
If this scenario is similar to your own, then what I have to share may be of use to you.
I figured that despite my diligence the parasite had not been flushed out. About three months later, I retested and discovered that all parasites were gone. Huh? Why was I still feeling so terrible?
I started looking laterally and after a great amount of research, I came upon a fairly newly diagnosed illness: Fructose Malabsorption a.k.a. FructMal.
It's similar to Lactose Intolerance, but in this case, the body loses the ability to digest Fructose. The symptoms are quite similar (identical) to those cited for Blastocystis Hominis.
While there isn't a single "cure" for the disease, the rules for the diet are relatively clear and once you understand them, it can lead to a complete elimination of symptoms!
What's going on?
Fructose can only be digested by the liver whereas glucose can be digested directly into the blood stream. In FructMal sufferers, the ability to process fructose is inhibited. The molecules are not absorbed in the small intestine, so they continue on to the large intestine. Once there, the free Sugar is rapidly devoured by the normal bacteria (probiotics) in your gut. This creates the abdominal distress that many sufferers experience.
I hope that makes sense so far.
The reason that all of my symptoms went away after the triple cocktail - was not only that the blasto was eliminated, but so too was all of the probiotic bacteria. It took about two weeks for my flora to rebuild (and with it the symptoms).
Apparently, FructMal is a fairly common ailment and like Blastocysits is not yet widely known about.
There are three important things to understand about FructMal:
1) The presence of glucose allows fructose to be absorbed (so long as the quantity of glucose is equal to or greater than the fructose). Table Sugar contains 50% of each. High fructose corn syrup (obviously) does not. So you can eat any food (i.e. table sugar) that has more glucose in it than fructose (almost). As a resource, I found this website indispensable: http://voluntocracy.org/Fructose/
It lists over a thousand foods with glucose/fructose ratios. Sensitivity (tolerance) varies from person to person, but foods with "0" or less on the chart are safe to eat (providing you also check them against the following two condition).
2) Fructans is another fancy name for complex chains of sugars that are bound up in a food. These are in wheat and a number of other grains. So, even though they are fairly balanced Sugar wise, they are inedible. White rice, oats, corn and potatoes are examples of carbohydrate rich foods that are safe to eat.
3) Sorbitols, xylitols, etc. inhibit the absorption of fructose, so even if you have a glucose excess, ingesting -ols can cause you problems.
If you think this might be the condition that you are experiencing, there is a test for it. It's usually called a 'hydrogen breath test.' The test measures hydrogen and methane present in the breath after ingesting fructose. Their presence equates to a positive diagnosis.
I am not affiliated with, nor have I used their service, but if you are not able to find a testing agency locally, they may be a resource for you. The test costs about $120.
If you choose to investigate this condition through your diet, a dietician may be of some help. Please be aware that food reactions /symptoms can remain in your body for 3-4 days, so if you are adding new foods to your palette of "safe" foods, then you will want to do so a few at a time.
As a tool for myself, I put together a food diary where I list the foods that I have eaten and the degree of reaction to them. It allows me to better understand my sensitivities - which vary from person to person.