2008

Medical literature shows that detection of Blastocystis hominis increases significantly when three fecal samples, collected in jars which contain liquid fixative. According to medical literature three samples are 70% - 83% accurate. ... Ten samples is 90-100% diagnostic. (Kean & Malloch, 1966).

The fixative prevents morphological changes once the parasite leaves it's host. These changes can render the parasite unrecognisable by the the lab, resulting in a false-negative.

Accurate identification of Blastocystis hominis requires special laboratory staining methods. These stains are not routinely used by Australian or UK laboratories ...

Intermittent shedding:
The number of parasites present in fecal samples fluctuates widely on a daily basis. On some days the number of parasites excreted in feces may be too low for detection by lab technicians.

Rectal Swabbing (Anoscopy)
Another method of parasite detection is, anoscopy or rectal swabbing. This technique involves scraping inside the rectum area with a small brush, preserving the contents in liquid fixative, and sending the samples to a reputable laboratory for testing.

Anoscopy is claimed by doctors who use it to be far superior in the detection of Blastocystis hominis when combined with stool sampling. The number of doctors who use this method are few and it's effectiveness as a technique for diagnosing parasites is generally disputed by medical experts. However, there have been a number of reports to this site of people who tested positive to Blastocystis hominis and other parasites only by this method. ...

Although US labs are now required by law to use the specific tests necessary for detection of Blasto. hominis and Dientamoeba fragilis, and to report their presence when found, this is not the case in many other countries.

The majority Australian, New Zealand, Canadian, UK and labs in other European countries do not employ the specific types of testing methods, nor do they employ technicians skilled in the detection of these parasites. Many of these labs do not report the presence of Blasto. hominis when detected in stool samples.

Failure to report the presence of Blasto. was documented by the Canadian Centre for Disease Control in 2001: ....

Specialised testing is not routinely used for patients with digestive disorders. The majority of those with digestive symptoms are misdiagnosed as suffering from Irritable Bowel Syndrome. ...

Many doctors believe that that Flagyl is the "gold standard" treatment for bowel infection. This theory is not supported by published literature.

NOTE: Parasites adhere to the bowel.
Using a special laxative helps force parasites out of the bowel and increases the detection rate.
Purging info. available here
http://www.badbugs.org/parasite/purged_testing.htm

.. The following products are proven not to interfere with test results: Fleets Phospho-Soda, Golytely, Nulytely (USA and Canada), Picoprep (Australia), Picosulphate (UK), and Klean-prep (European, African and Middle, Far Eastern countries and Canada). ..

Randomly select small pieces from the last portion of the stool.
Studies have shown more parasites reside in the last half of the stool than the first half.

Ingestion of some products prior to collection of faecal sample may interfere with the detection of parasites. These include tetracyclines, sulfonamides, antiprotozoal agents, laxatives, antacids, castor oil, magnesium hydroxide, barium sulphate, bismuth kaolin compounds, hypertonic salts, mineral supplements, anti-parasitic herbs, antibiotics, antacids, antidiarrheals, enemas, and intestinal radiocontrast agents may interfere with recovery of the parasite. All of these should be avoided 3 weeks before submitting samples. ...

Blastocystis hominis may be the most common parasitic infection of humans.
This organism is often missed on stool examination but grows luxuriantly in all the media used to cultivate xenic Entamoeba.