Physicians should be concerned about the competence of the labs to which they submit samples, and be better informed of techniques used routinely by the laboratory before accepting positive or negative reports at face value. It may well be that many cases of abdo. distress of hitherto unknown etiology are, in fact, due to D.fragilis.
Am. Journal of Trop. Med. & Hygiene. 1975 Vol 26, No 1

‘Diagnostic procedures employed currently in laboratories around the UK are not optimal for the detection of D. fragilis and B. hominis’
D. fragilis and B. hominis: neglected human protozoa. J. J. Windsor. The Biomedical Scientist. July 2007. Pages 524-27.

Relatively few laboratories in England and Wales use suitable staining methodologies; consequently, many are likely to encounter B. hominis initially in unstained preparations. In fact, many of the cases of B. hominis seen in our laboratory are found by direct microscopy and confirmed subsequently with a trichrome stain. In view of this, it may be pertinent to address proficiency to detect B. hominis by the ability to report it both in unstained and stained preparations.
British Journal of Biomedical Science, 2001. Windsor, J J, Marfarland, L, Whiteside, T M

It is our impression that the variations in the reporting of D.fragilis reflect more the attention that is paid to the parasite and the technique that is used than to the actual incidence.
The Neglected Amoeba: Dientamoeba fragilis. A Report of 100 "Pure" Infections. Kean & Malloch. American Journal of Digestive Diseases. New Series, Vol.11 No.9. 1966

As B.hominis is the most common faecal parasite seen at both Aberystwyth PHL and Swansea PHL in the UK, we feel that the CDSC figures do not reflect the true incidence of B.hominis in England and Wales. Indeed, all 139 reports of B. hominis reported to CDSC Wales in 2000 were detected by our two laboratories (unpublished data). We believe that this can be attributed to laboratory awareness and the use of suitable ethodologies.
JJ Windsor, et al
British Journal of Biomedical Science 2001; 58: 129-130

A single stool specimen examination will miss many pathogenic protozoan infections in symptomatic persons (RA Hiatt et al, 1983)

The higher prevalence of D. fragilis infections than that of G. duodenalis is probably related to the method used, a procedure, which is rarely followed in laboratories for the diagnosis of enteric parasites. These epidemiological data suggest that when faecal samples are examined after a period of time and without Giemsa staining, most D. fragilis infections goes undetected.
Dientamoeba fragilis is more prevalent than Giardia duodenalis in children and adults attending a day care centre in Central Italy.
Crotti D , D'Annibale ML , Fonzo G, Lalle M , Caccio SM , Pozio E .
Parasite. 2005 Jun;12(2):165-70.

Even under ideal circumstances, a single stool specimen is diagnostic only 50% to 60% of the time; three samples increases the sensitivity to 80% and six samples to 95% .
Vol. 18, No. 4 The John Hopkins Microbiology Newsletter.
Monday, January 25, 1999

Our results suggests that a single stool specimen examination will miss many pathogenic protozoan infections in symptomatic persons
Hiatt RA, Markell EK, Ng E
American Journal of Gastroenterology 1983 Oct;78(10):634-6

Since the number of organisms are reported to vary daily, a series of stool samples for ova and parasite examination should be collected.
D.fragilis: A Gastroeintestinal Protozoan Infection in Adults
Spencer et al
AMJ., Vol 77, No. 8. 1977 2002

Many laboratory technicians, however, are unfamiliar with the appearance of this parasite, either living or in stained preparations, and it is still frequently misdiagnosed as an amoeba.
Intestinal Parasites of Some Diarrhoeic HIV-Seropositive Individuals in North Brazil
Mem Ins
t Oswaldo Cruz, Rio de Janeiro, Vol. 94(5),Sept./Oct. 1999: pp 611-613

The laboratory reports of the Communicable Disease Surveillance Centre show that in 1992, 68 cases of D fragilis infection were reported from seven laboratories and that by 1996 this figure had increased to 231 cases reported from 20 laboratories (unpublished data). These results reflect an increase in the number of laboratories performing faecal stains. It can be assumed, however, that the true incidence of D fragilis infection is many times higher: there are an estimated 450 diagnostic laboratories in the United Kingdom, most of which do not look for this pathogen.
Letter to BMJ 1999; 318:735 (13 March 1999). J J Windsor, Senior biomedical scientist & E H Johnson, Associate professor.

The proper collection and preservation of multiple stool specimens in addition to adequate microscopic examinations by qualified, trained individuals are necessary for the identification of D.fragilis.
Spencer et al: Am.J.of Gastro. 1982

Although DF is thought to be uncommon, surveys indicate that it's occurrence is worldwide. In properly collected and preserved stool specimens examined by lab. personnel trained to recognize this flagellate, the incidence of this organism corresponds to that of Giardia lamblia. It is particularly important that permanently stained slides of stool specimens in addition to adequate microscopic examinations by qualified individuals are necessary for the identification of DF.
Dientamoeba fragilis - an intestinal pathogen in childre? (Am J Dis Child 133:390-393, 1979)

Generally considered rare and either not found in surveys, or recovered in small proportions only, we have, since the adoption of a two bottle collection kit for faecal samples, found it almost as common as Giardia lamblia
D.Fragilis: A Review with Notes on its Epidemiology, pathogenicity, mode of transmission and diagnosis by Yang & Scholten (1976)

...physicians should perhaps be more concerned about the competence of the labs. to which they submit samples and be better informed of techniques used routinely by the laboratory before accepting positive or negative reports at face value. It may well be that many cases of abdo. distress of hitherto unknown etiology are, in fact, due to D.fragilis.
A Yang & Scholten,
Am. Journal of Trop. Med. & Hygiene.
Vol 26, No 1 . 1975

"Because competence to accurately diagnose parasitic infections is not easily obtained, physicians should perhaps be more concerned about the competency of the laboratory to which they submit their samples"
Yang & Scholten, D.fragilis: A review with notes. Am.Journal of Trop. Med. & Hygiene 1977

Our results suggest that a single stool specimen will miss many pathogenic protozoan infections in symptomatic people.
How many stool samples are necessary to detect pathogenic intestinal protozoa? Hiatt RA et al. AJTMH 1995

Because the time during which this organism remains in a recognisable condition in stools is limited, samples must be examined shortly after defecation, or be bulk-preserved in a suitable fixative immediately after a bowel movement.
Yang & Sholten, Am.J. TM&H Vol 26, No.1 1975

D. fragilis is believed to be rare; however, when stool specimens are collected and preserved in polyvinyl alcohol or other fixative, followed by permanently-stained smears, the recovery rate increases markedly, particularly when smears are prepared and examined by well-trained laboratory personnel .
Dientamoeba fragilis; A gastrointestinal protozoan infection in adults. Mary J. Spencer, M.D., Martha R. Chapin, R.N., and Lynne S. Garcia, M.T.(ASCP) Am. Journ. of Gastro. Vol. 77. No. 8, 1982

Diagnosis is best made by finding the characteristic trophozoite on a permanently stained faecal smear as it is not reliably detected on direct wet prep. microscopy or a faecal concentrate ......Patients collect their stool specs. at home into polyvinyl alcohol fixative to ensure that there is minimal degeneration of the protozoan while the spec. is being transferred to the lab. Three specs. are collected on different days to increase the chance of detecting intermittent excretion of the protozoan.
Dientamoeba fragilis: A Bowel Pathogen? New Zealand Med. Journal. 11 Feb. 1987. p 4-65 Oxner, Paltridge, Chapman, Bramwell Cook, Sheppard.

Unreliable identification of D.fragilis may explain variations in the results of different studies. Even in stained faecal smears, which must be prepared from fresh material (Ockert, 1990), Dientamoeba may be confused with amoeboid forms of Blastocystis, Endolimax and other organisms, or degenerated polymorphonuclear leucocytes. (Markell et al., 1986; Ash & Orihel, 1990.) Trans of the Royal Society of Tropical Medicine and Hygiene (1993) 87, 163-165. Nongyao Sawangjaroen, et al.

"The prevalence of D. fragilis in most localities is poorly documented, as the methods commonly used in intestinal parasite surveys are unsuitable for detecting trophozoites"
J.Clinical Parasitology 9th Ed. Beaver, Jung & C upp 1984

Eight counties in Washington accounted for 72% of all DF cases. The distribution of reported cases by county in Washington differed significantly from the number of stools submitted for examination from these counties. A possible explanation is that stool specimens from the eight counties are routinely sent to the Washington State Public Health Lab (WSPL) when examination for ova and parasites is indicated and stools from other counties are not. In 1985-86 all reported DF diagnoses occurred at the WSPHL. At this time only a few labs in the state, including the WSPHL, reported using the stool collection and examination techniques necessary to detect DF (unpublished data) . In addition, an increased awareness of DF existed among health care providers in San Juan County due to a cluster of cases there, which probably resulted in increased stool spec. submissions.
Descriptive features of Dientamoeba fragilis infections. J. H. Grendon, R. F. Digiacomo and F. J. Frost. Journal of Tropical Med & Hygiene 1995, 98, 309-315

"A single stool specimen examination will miss many pathogenic protozoan infections in symptomatic persons." RA Hiatt et al, 1983

"I'm almost crying as I read your story on the site. My doctor has continuously diagnosed me with IBS and is on the verge of telling me I'm wasting his time every time I go in there. I had one stool sample sent to a lab last year in April and the results showed nothing, so I took their word for it. Last night, my pain was so bad, I almost stuck a knife in my chest to end it. No one listens to me. My family says it's all in my head. My doctor tells me it's IBS. Now that I've read your story, I have some hope." (2009)

"My son who is now 21 has battled “IBS” for three years after a trip to Mexico.  Just like everyone else, FOBMAP diet, camera inspections etc.  Now they have him on Elavil an antidepressant but to no avail.  I can’t believe that no one has considered a parasite problem, just nothing else seemed to work or make sense so the gastro has assumed he must be stressed with anxiety from college so lets try Elavil.  (My son is confused as to why he’s taking an antidepressant as he has never felt over stressed, let alone anxious.). It’s incredibly frustrating and now  I can’t even get a doctor to order tests for blasto or d fragilis.  As you can relate,  his diarrhea, gas and intestinal pain limit his life tremendously.   He can’t even eat out in fear he will have to hit the restroom before the car ride home.  (UK. April 2016)

Diagnosing parasites:

If you suspect you might have parasites but standard stool testing run by your doctor is coming up negative, then request PCR testing. PCR is a much more sensitive test than microscopy. Until recent years it was only available as a research tool: patients had no access to this highly sensitive test. PCR is based on molecular screening of individual parasites rather than detection of parasites based on examination of stool under a microscope, which makes it costly in contrast to the broad range of parasites that can be detected with microscopy. However, that problem seems to have been overcome with the new Multiplex PCR Test that detects seven intestinal parasites - including D.fragilis and Blasto. PCR detects parasite DNA, making it more accurate than the triple feces test. More about the TFT below.


Metametrix, a US based lab who specialise in PCR testing, will soon merge with Genova Diagnostics, according to their website. More about Genova below.

Warning: I've heard from many people who paid a large amount of money to end up with a result from Metametrix of 'parasite of unknown taxonomy', which is not helpful!

If you don't have access to, or cannot afford the cost of PCR testing rest assured that the triple feces test (TFT) finds most - upwards of 80% - of Blasto. and D.fragilis infections. If initial results are negative, submit another batch of 3 fixed samples. I've heard from plenty of people who tested positive only after submitting 6 samples.

Recommended labs for the Triple Feces Test (TFT):

Histopath Labs, Sydney.
Level 4, 97 Waterloo Street
North Ryde.
Ph: 02 9878 8111
Fax: 02 9878 8300

Histopath's standard testing kit includes 3 vials with the all important fixative. Histopath send their kits anywhere in Australia and overseas. This lab was was the first Australian lab to act on the problem of underdiagnosis by always providing fixative with their kits - as recommended in decades of D.fragilis and Blasto. medical literature.


In the early '90s Genova Diagnostics (formerly Great Smokies), a US based lab with agents worldwide, was the first to make available to patients the type of specialised stool testing recommended in decades of D.fragilis and Blasto. medical literature as essential to diagnose these parasites. In the UK (but the same could be said of most western countries) diagnosis was nearly always made by alternative therapists (see below). The NHS don't offer this type of testing, and still doesn't (2016).

However, a Great Smokies diagnosis, a lab who were saving many people from years more sickness, was often met with incredulity or dismissed as meaningless by doctors who held certain pejorative views about GSD, which was the majority. Collectively GSD was condemned by mainstream medicine as a "dodgy" lab because they were diagnosing what were largely considered as 'unimportant' parasites.

A high prevalence of Dientamoeba fragilis is reported in faecal samples collected from patients attending complementary medicine practitioners in the British Isles. For further work on its pathogenic role and prevalence among patients with gastrointestinal symptoms, immediate collection in SAF should be considered the optimal sampling modality for UK based laboratories.

Prevalence of Dientamoeba fragilis among patients consulting complementary medicine practitioners in the British Isles. J Clin Pathol 2009 Feb;62(2):182-4. Schuster and Jackson

Website: Genova Diagnostics.

Less costly than Genova is The London School of Hygiene and Tropical Medicine who diagnose Blasto. and D.fragilis by the TFT. You need a doctor to arrange the test:

London School of Hygiene & Tropical Medicine:
Phone: 0207 927 2427


If you find yourself at the Tropical Medicine Hospital in London clutching a positive result for Blasto. or D.fragilis from The London School of Hygiene & Tropical Medicine, then don't be suprised if the Hospital consultant advises that Blasto. and D.fragilis are unlikely pathogens, and that if a cure is achieved the result is most likely coincidental(!).

For patients in the UK with D.fragilis and Blasto this unfortunately still holds true in 2016:

‘Diagnostic procedures employed currently in laboratories around the UK are not optimal for the detection of D. fragilis and B. hominis’
D. fragilis and B. hominis: neglected human protozoa. J. J. Windsor. The Biomedical Scientist. July 2007. Pages 524-27.



Blasto. and D.fragilis are fragile parasites that begin to break apart soon after evacuation, and in the process become unrecognisable. Fixative improves the accuracy of stool testing by preserving the structure of the parasite making it easier for the lab to identify.


Blasto. produces hardy, thick walled cysts. These cysts act as protective vessels for the parasite and can survive at room temperature for up to 19 days (Moe et al 1996) and in water, including water which has been chlorinated.

D.fragilis, on the other hand is thought not to produce cysts and unlike Blasto., can not survive in water.

The human pinworm Enterobius vermicularis is suspected to play a role in helping this parasite survive the journey through the human gut. However, recently D.fragilis cysts have been identified in in rats infected with human D.fragilis. Transmission of Dientamoeba fragilis: pinworm or cysts? Trends Parasitol. 2014 Mar;30(3):136-140. doi: 10.1016/ Epub 2014 Jan 31. Clark CG, Röser D, Stensvold CR.

Blasto. is diagnosable in fresh, unfixed samples, but it is often the hardy cysts which are identified, not the parasite. Studies show that intermittent shedding of cysts is a problem and contributes to false negative results. More below.

Interesting fact: The existence of the cyst form was not confirmed until the early 1990s.

Fixative increases the likelihood of diagnosis because it enables all forms of Blasto. to be identified, not just the cysts.

However three samples is not a 100% diagnostic

Three fixed samples is up to 80+% diagnostic. B.H.Kean, M.D., C.L.Malloch, MD. Am.J.of Dig.Dis. Vol 11, N o.9, 1966

Even under ideal circumstances, a single stool specimen is diagnostic only 50% to 60% of the time; three samples increases the sensitivity to 80% and six samples to 95%. Vol. 18, No. 4 The John Hopkins Microbiology Newsletter. Monday, January 25, 1999

"As far as the 3-sample rule is concerned it is not 100% accurate. It has been shown to vary depending on the organism but 3 samples are enough to detect 95+% of infections for most of them. That still leaves some undetected of course. I have heard (anecdotally) of someone who had Giardia diagnosed only after 8 samples!" (Comment by parasitologist from the London School of Tropical Medicine & Hygiene. 2002)

This problem occurs because:

A number of patients may intermittently shed protozoa in their stool. Similarly, some protozoa (G. intestinalis and D. fragilis) have been shown to have highly variable and intermittent shedding. (van Gool et al., 2003)

There is marked fluctuation in the shedding of the parasite from day to day, varying from as high as 17 to 0 per x40 microscopic field. The cystic stages when estimated in 8 Blastocystis-infected individuals ranged from as high as 7.4x10(5) cysts per gram of stool to 0. (Parasitol Res. Vennila GD, et al. 1999 Feb;85(2):162-4)

The number of organisms excreted daily flucuated markedly in the one case investigated. Dientamoeba fragilis, a review with notes on its epidemiology, pathogenicity, mode of transmissino and diagnosis. Yang & Scholten, Am J Trop Med Hyg. 1977 Jan;26(1):16-22.

The solution: Wait a few weeks and retest.

Not everyone is given the option to submit stool samples in fixative:

"My tests came back negative though I am not convinced they were done correctly. My request for the three day liquid suspension was denied by my naturopath who apparently knew better. The guy she had do the testing was an independent who apparently is some kind of expert in this and he doesn't believe the liquid suspension necessary. I fear I wasted $80 odd." (Australia. November 2005)

One Australian pathology lab had no idea about fixative and the vital role it plays in diagnosing parasites:

"We spoke to a pathologist about the liquid fixative that should be in the stool tests but they had not heard of it before. What exactly is it?" (Australia. November 2005).

A lab in Western Australia had to be educated about the importance of fixative by a patient:

"I went to my doctor today and told him that I wanted the tests. I went to my local path collection centre and spoke to the lovely lady to get the fixative. She rang the microbiologist at the Perth lab and he said that I didn't need a fixative. Because I went armed with the relevant printouts of your website re lab testing she was convinced and told the microbiologist that 'the client has quite a lot of information about this and it all indicates that a fixative is needed'. After she found out that they did actually have the fixative in stock she talked him into couriering it out to her collection centre and I pick it up tomorrow! (September 2007).

If your stool samples are negative but your symptoms persist - retest. It's absolutely essential not to take a negative result at face value. In one case a woman spent over a year thinking D.fragilis had been eradicated because her first and only batch of 3 fixed samples post treatment were negative, despite the fact that she was still very unwell. Her doctor put her symptoms down to IBS. A year later, after recontacting, she was retested and D.fragilis turned up again. This is not an isolated case.

In 1996 researchers tested subjects already positive for D.fragilis with the aim of assessing the accuracy of stool testing, The authors concluded that testing 10 samples is necessary to achieve 90-100% accuracy. (Kean & Malloch. 1966).

The idea that Blasto. causes symptoms is still considered controversial in medical circles (2014). As a consequence not all labs routinely search for this parasite, whilst others have been known to exclude Blasto. in their results or fail to report Blasto. if found in low numbers. People from Canada, Australia, the UK and other European countries have encountered this problem. This problem is also documented in the medical literature:

Not all laboratories routinely searched for B. hominis. The provincial reference laboratory for parasites reported all parasites found in the samples. In only two of the seven other laboratories was this also done. The five remaining laboratories (involving samples from seven day-care individuals) later stated that they did not actively search for, or report, B. hominis as a matter of course because it was not believed to be pathogenic. BLASTOCYSTIS HOMINIS: A NEW PATHOGEN IN DAY-CARE CENTRES? Canada Communicable Disease Report - Volume 27-09, 1 May 2001


Stool samples were collected from 17 symptomatic patients to test for parasites. All patients had at least one of the following symptoms: nausea, vomiting, diarrhoea, abdominal cramps, bloating. Two stool samples were requested for testing at the Provincial Reference Laboratory (a public laboratory in Canada). A further 10 symptomatic individuals were evaluated by their physicians and 2 stool samples from each were sent to 7 different laboratories:


The govt. lab reported all parasites found in the samples, but 5 private labs DID NOT report all parasites, in particular Blastocystis hominis, as they believed this parasite was non-pathogenic and therefore they did not actively search for it. If it was found they did not report it to the treating physician. B. HOMINIS: A NEW PATHOGEN IN DAY-CARE CENTRES? Canada Communicable Disease Report - Volume 27-09, 1 May 2001

A Canadian man read about the shortcomings of standard stool testing on this site - which led to Blasto. being diagnosed. After a combination of Flagyl, Bactrim and Iodoquinol he tested negative, yet his symptoms persisted. Three years passed before he read about the problem of under-reporting on my site. After recontacted the lab he was told that that just prior to submitting his (post-treatment) samples the lab had implemented a policy of non-disclosure which meant that they no longer inform the doctor that their patient is infected with Blasto. Meanwhile, believing he was no longer infected he consulted 45-50 doctors in an attempt to find out why he was still unwell. ( December 05)

This man had a similar problem:

"In November 2006, 8 months ago, on a Saturday evening, I drank a little quantity of water (it fitted in the palm of my hand) that was brought back by somebody from an ashram in India. I was told that the water was safe to drink. I started having problems a few hours after that. The Tuesday after, I went to a traveler's clinic to meet a doctor that knows about parasites. 3 samples of my stools were analysed in the 2 weeks that followed. Since nobody called back, I called the doctor and he informed me that they had found the Blastocystis hominis in my stools and that there are no symptoms associated with blasto. That is why he didn't call me back." (USA. July 07)

Purged samples:

"The only test that has ever worked for me is the purge" (USA 2001)

Some people only test positive after purging.

Purging involves drinking a strong laxative to force parasites out of the bowel. This study from 1986 shows that parasites lodge in the cecum, a small pouch at the beginning of the large intestine:

Intestinal parasites seldom colonize the lower colon, and therefore, purged stools appear to be more efficient for finding parasites residing in the cecum. The terminal portions of stool collected from our purged patients yielded the highest number of B. hominis organisms, and this finding suggests that B. hominis has a propensity for cecal colonization, as does E. histolytica." (Sheehan et al. Clinical Microbiology. 1986)

Not all laxatives are suitable. Some intefere with lab stains.

Safe laxatives are: Fleets Phospho-Soda*, Golytely, Nulytely (USA and Canada), Picoprep (Australia), Picosulphate (UK), and Klean-prep (Europe, African and Middle, Far Eastern countries and Canada).

Important: Avoid when submitting samples for PCR testing. More about PCR below. Read My Disclaimer. Always check with your dr and the lab before taking any products which cause diarrhoea.

Culturing samples

Labs will do this on request if there is a suspicion of parasites.

Culturing consists of placing a stool specimen in a special media which encourages the organism to grow. It's not routinely done by labs because it is time-consuming and therefore more costly to perform. Pathology labs are as concerned with their bottom line as much as any other business. Fixative and culturing adds to their costs.

Fixative kills D.fragilis - therefore it's not possible to grow parasites in stool samples collected in fixative. (Biological, Clinical, and Diagnostic Aspects of Dientamoeba fragilis. Eugene H. Johnson, Jeffrey J. Windsor, and C. Graham Clark. Clinical Microbiology Reviews, July 2004, p. 553-570, Vol. 17, No. 3). In that case the lab will supply a sample jar without fixative.

The following medical studies show the value of culturing stool samples:

It is important to subculture, even if protozoa are not seen in the primary culture, the first subculture often detects more infections with D. fragilis and Entamoeba species than does the primary culture (Ockert, 1990).

Without culture, we would have overlooked the organism in 2 of 4 infected stool samples. Even so, we probably underdiagnosed the infection by examining only one stool sample from each patient. The number of D. fragilis in faeces can vary widely from day to day. (Desser & Yang, 1976).

Culture contributes even more to the diagnoses of D. fragilis infection. Silard et al (1979) found faecal culture to be more than 5 times as sensitive to microscopy in detecting Dientamoeba and E. histolytica infections, and Ockert (1990) reported still greater i ncreases in sensitivity. Diagnoses by faecal culture of Dientamoeba fragilis infections in Australian patients with diarrhoea. Nongyao Sawangjaroen, et al. Transactions of the Royal Society of Tropical Medicine and Hygiene (1993) 87, 163-165.

The use of culture techniques may increase detection of D.fragilis signficantly, with reported cases as high as 18.1% in Israel, 36% in Holland and 41.5% in Germany. Dientamoeba fragilis: the unflagellated human flagellate. Jeffrey J. Windsor and Eugene H. Johnson. British Journal of Biomedical Science 1999; 56: 293-306


More Examples of Bad Medicine:

Access to even basic stool testing will be denied patients if their doctor considers B.hominis or D.fragilis to be harmless, as in this case:

"I've tested positive for Blastocystis Hominis, I even managed to get a treatment with Flagyl but the symptoms remain. When asking for a re-test to confirm if Flagyl worked or not they say that since Blasto probably isn't the cause of my problems, there's no reason for another test. According to them I have already gotten more treatment than they normally give for Blasto, since they almost never treat it... Now I've been prescripted "LuneLax", fibre, since they think I have IBS. Been eating fibre for a month and I can't say it helps. My symptoms are: Fatigue, diarrhea, abdominal discomfort, flatus, dizziness, light head ache (occasionally), muscle/joint ache (occasionally), rectal itching (occasionally).
So, I'm caught in the middle, can't get tested nor any treatment since "Blasto isn't the cause of my problems". Even though I was treated with Flagyl I'm fairly certain that I still carry Blasto, I still have symptoms anyway... "
(Sweden. Nov. 2005)

Some people have had to be very resourceful in their approach to pursuing a diagnosis of D.fragilis or Blasto.

For instance, three and a half years after falling ill, Yvonne, from New Zealand, was diagnosed with D.fragilis. Her symptoms - diarrhoea, bloating, flatulence, dizziness, headaches, extreme fatigue, body aches & pains, dry cough and heart palpatations left her too incapacitated to work.

She was asked to submit a single (unfixed) stool sample. Not suprisingly the result, which came from one of New Zealand's most high profile pathology labs, was negative.

So too was a stool antigen test for Giardia.

Despite the negative result, her doctor prescribed Flagyl in case Giardia lurked undetected. Her symptoms came back only a few weeks after taking Flagyl. The treatment was repeated but this time the symptoms persisted .

Understandably Yvonne felt "very alone" trying to cope with her seemingly undiagnosable and untreatable symptoms. "Family and friends are tired of hearing about my health problems (and I don't blame them)".

Three years later, Yvonne stumbled upon my site where she discovered that specialised stool collection and testing methods are necessary to diagnose the two most common, but underdiagnosed GI parasites: D.fragilis and B.hominis.

Armed with this new information Y. phoned her doctor's "mainstream, high profile lab" to find out about their testing recommendations for D.fragilis and B.hominis:

"I was told by a microbiologist that Bh was "just a fungus" and Df was "self limiting". I told him that I had published research that proved otherwise. I said they could cause chronic illness that could last for years. I told him that I suspected I was suffering from one of these bugs because I had been sick for 3 1/2 years and my symptoms matched those of a parasitic infection. He replied "well you can make your symptoms match any disease you want to, can't you?" He told me I was interrupting an important meeting he was in and hung up."

Getting nowhere with conventional doctors, Y. asked her naturopath — who had treated her unsuccessfully for a couple of years — to arrange testing with the specialist lab Great Smokies Diagnostics (now Genova) - a lab much maligned by much of the medical community in the 90s.

Dientamoeba fragilis was diagnosed in the last two of the three fixed samples. She took the result to her GP:

"My GP had never heard of Df and she asked me to leave the info with her so that she could make a few phone calls and she would get back to me. She phoned me back this morning and told me that Great Smokies was a "dodgy lab" and not recognised by the medical establishment."

The GP's advice was swayed by the microbiologist's view that: "It is most likely not the Df that is causing my symptoms - (he doubted) that I even have it."

Yvonne found herself in the same situation she had read about on this site - diagnosed with D.fragilis or B.hominis but unable to overcome medical dogma.

After much searching she eventually located a more open-minded GP three hours drive away. Yvonne hoped he would take her D.fragilis into account when diagnosing her symptoms.

The new GP was "very helpful and open-minded", but he had never encountered a patient infected with this common parasite. He admitted he was "not an expert", and was therefore unfamiliar with specialised drugs necessary to eradicate D.fragilis.

Sensibly she declined his offer of taking doxycycline and metronidazole (Flagyl), based on the fact that her infection was diagnosed after two rounds of Flagyl.

Determined to prove to her doctor and microbiologist the validity of the stool collection and testing methods recommended in the published medical literature and used by Great Smokies, she found a lab who agreed to test two stool samples without fixative and three with. The fresh, unfixed samples, tested within two hours of evacuation, were both negative. The second of the three fixed samples was positive for D.fragilis.

Yvonne phoned her new "open-minded" doctor with the good news:

"..although he was surprised that I was so happy about the result - he didn't really seem to understand why I had gone to the trouble of being re-tested by (the private Auckland lab) after the positive GSD result. I told him I want my medical records to include the positive SCL result because I am so annoyed about all the previous negative results I had had by Auckland's major lab - and I am also annoyed that most of the medical establishment view GSD as being "a dodgy lab" - I wanted to prove that GSD were right and show my doctor how difficult it is to be tested correctly. I wanted to be re-tested by SCL - so that I could be certain that they were using the correct testing techniques so that other people can also be confidant in their parasitology testing methods. However after all that effort, when I asked the SCL lab if they could now test two other people - they said that the specific testing methods required to test for Df had been too time consuming."

Unable to find a doctor to take her D.fragilis diagnosis seriously Yvonne was forced to self-treat by ordering her meds online*.

One month after her treatment Y. wrote to tell me that for the first time in over three years she was "FEELING REALLY WELL. All my body aches & pains have gone, the nausea has totally gone, my bowel is returning to normal, I can get through the day without having to lie down, my energy levels are way up and my head feels mostly clear." May 2003.

* Buying meds online is not a good idea.

The ingredients may either not be pure, or the drugs might be fake or contain only small amounts of the drug. Exposing Blasto. to less than the recommended dosages is a great way to end up with a treatment resistant infection. Having said that I know how desperate people can get. If I had found such a treatment online I would have gone to Mexico to buy them, as many people are forced to.

"(My) doctor has no experience in treating (Blastocystis hominis). In fact he says it is so rare that he hasn't seen or heard about it in 30 years!". NY, USA. Jan. 2006


"I asked my doctor for B. hominis and D. fragilis testing, she thought I was crazy and refused." US woman with chronic digestive symptoms. USA 2003


"The doctor said that parasites do not exist." Northern Queensland, Australia. October 2005


"My gastro. eventually came around to say only in 'rare' cases is df a pathogen and he's never seen it in all his 25 years". US, 2003


"I've been testing for Ova and Parasite for 15 years and have never seen anything in the USA. " Specialist gastroenterologist's response to his patient's request for parasite testing to determine cause of chronic digestive symptoms. (2005)


"The Doctor said to my husband today that he had never heard of this bug." Canadian diagnosed with Blasto. April 2005.


"Thanks to the info on your site my doctor has allowed me to get my stool testing done at the local hospital wich apparently has a much better testing facility. He's also let me assist in determining how to do the testing (ie. several seperate screenings over the period of a week) as opposed to the single screenings done in the past. This is great news for me cause I was looking at spending $600 to have it done through Great Smokies. D.fragilis was diagnosed. (USA 2005)


"I have been having parasite tests for 5 years with the national health here in the UK since spending two years in India. I have been unable to work or have any quality of life for nearly all of that time. I have finally been diagnosed with Dientamoeba fragilis as well as some additional bacteria and yeast by Great Smokes Diagostics. As with others I have been misdiagnosed, unbelieved and had numerous "normal" test results whilst living, or rather existing, with chronic fatigue, severe digestive problems, intermittent fever, nausea etc etc. C. UK. April 05


"My name is C. and I am 18 years old and I need some advice. I have been feeling really bad for many years now, I have fluid-retention, foggy thinking that is so bad it feels like I am constantly on drugs, heavy body and so on. The doctors just couldn't find out why and finally I did a parasite test with a naturopath. They found Dientamoeba fragilis. I have been to countless doctors these four last years, but no one has ever mentioned anything about parasites. I have gotten diagnoses like depression, adhd, hypothyroidism and so on. We actually once mentioned parasite infection, and the doctor only laughed at us. I have missed years of school work now because my thinking is so foggy.... It's really destroying my life. " Sweden. 2005


"I see what you mean about testing is only a small part of the battle." Canadian diagnosed with D.fragilis searching for medical help. Canada. Dec 2005