In patients diagnosed with chronic irritable bowel syndrome (IBS), faecal samples are placed directly into fixative and then stained with an iron haematoxylin. Using this technique, 40% of IBS patients were shown to be infected with B. hominis .
April 2002 - Biomedical Scientist.

Researchers found a significant number of IBS patients were infected with the parasite Blastoystis hominis The authors concluded "there was a set of patients with irritable bowel syndrome in whom the presence of Blastocystis hominis may not be incidental."
Eur J Clin Microbiol Infect Dis June 1999. Irritable bowel syndrome in patients with Blastocystis hominis infection.

A 1997 study found the symptoms of Blastocystis hominis — diarrhea, anorexia, and flatulence — resembled the symptoms of IBS. The researchers found levels of Blasto. hominis IgG antibodies were significantly elevated in patients with IBS compared with asymptomatic controls
Significantly increased IgG2 subclass antibody levels to Blastocystis hominis in patients with irritable bowel syndrome.
Hussain R et al

In well conducted surveys, including in developed countries, D.fragilis is as common as giardia.
Scholten & Yang,The Evaluation of Unpreserved and Preserved Stools for the identification and detection of intestinal parasites. Am. J. Clin. Pathol. 62:563-567, 1974

Hussain et al reported significantly increased IgG2 antibody levels in patients with irritable bowel syndrome.
Recent advances in B.hominis research: hot spots in terra incognita.
Kevin S.W. Tan, Mulkit Singh, Eu Hian Yap.
Int. Journal for Parasitology 32 (2002) 789-804

Superficial invasion and mucosal inflammation of the intestine with B. hominis have been observed in studies of gnotobiotic guinea pigs. Although controlled studies of the association between B. hominis and diarrhea are lacking, there have been studies that have examined the link between B. hominis and irritable bowel syndrome (IBS). Levels of IgG antibody to B. hominis were increased significantly in the patients with IBS compared with asymptomatic controls. This is suggestive of a link between B. hominis and IBS.
Irritable Bowel Syndrome: In search of an etiology: Role of B.hominis
Javed Yakoob et al
Am. J. Trop. Med. Hyg., 70(4), 2004, pp. 383-385

"Parasitic infection should be considered in patients with vague gastrointestinal symptoms".
Millet, V. et al. Dig Dis Sci 1983 Apr;28(4):335-9

"Blastocystis hominis was frequently demonstrated in the stool samples of IBS patients"
Am J Trop Med Hyg. 2004 Apr;70(4):383-5.

The symptoms of IBS are identical to the symptoms caused by Blastocystis hominis. Many theories have been put forard to explain the cause of IBS, including Because there is no known cause for IBS, Diagnosis of IBS is based on a set of symptoms, and IBS is not a not a defined disease with a known IBS is incurable, and apart from symptomatic relief for constipation or diarrhoea, the patient is left to endure an array of B.hominis symptoms until she or he finds a more open-minded doctor — or this site.

Irritable Bowel Syndrome (IBS) affects up to one quarter of the population in developed countries

Ninety-nine percent of people with Dientamoeba fragilis or Blastocystis hominis who contact this site have been diagnosed with IBS at some stage.

A diagnosis of IBS is based on a set of symptoms.

The symptoms of IBS and parasitic infections often identical. The likelihood of diagnosing a parasitic infection by testing one sample is less than fifty-percent (John Hopkins Microbiology Newsletter. 1999)

The advice for IBS is often to learn to live with symptoms, as the following message posted on an IBS message board, shows:

"I went to see my doctor about diarrhia, and pain and bloating. And she said, "You have ibs. There's nothing that can be done". About a year later, it was getting so bad I didn't even want to leave the house, I was getting so depressed, so I went back to her and said I wanted a second opinion, she sent me to a gastroenterologist. He listened to my complaints, and said to me "Well I have good news and I have bad news, the good news is I don't think you have cancer, the bad news is I think you have ibs and there is nothing I can do for you". So I went home more depressed than when I started out. (2002).

Over the years many theories have been proposed as a cause for IBS — the psychological need of sufferers to pass a large stool, (Achord, JL. 1979); psychological disturbance (Lea & Whorwell, 2003); abuse in childhood (Talley et al, 1998); chemicals in water (A.K. Susheela, et al. 1992), etc.

Parasites on the other hand, rarely rate a mention in IBS literature. An example is the Gastroenterology Society of Australia's IBS patient handbook, and the Australian IBS support group IBIS website. Neither mention the possibility of parasites. Curious really, considering that a number Blastocystis hominis and Dientamoeba fragilis studies show these parasites are common in patients with IBS. Neither do these sites mention anything about the specialised stool testing necessary to diagnose them. The Gastroenterology Society's Patient Handbook even advises that testing is unnecessary(!) if symptoms are typical of IBS.

This man was told his symptoms were due to IBS, but specialised stool testing revealed an infection with both Dientamoeba fragilis and Blastocystis hominis:

"I first became ill around 18 months ago. My symptoms included stomach pains loose bowel movements and nausea. The GP gave me pills to reduce stomach acid and told me I might have IBS and not to worry as the symptoms would go away given time.

I explained my symptoms to a naturopath who told me straight up "You have a parasite" She gave me some herbal medicine that initially helped but soon after I ceased taking the herbs the symptoms returned. I changed GPs and a stool test found that I had (high levels of) D.fragilis. Three courses of Flagyl later I not only still had D.flagilis I also now had the blastocystis appear in my stool test." (October 2005)

Since the site began in 2001 the majority of people diagnosed with a parasite were incorrectly diagnosed with IBS, as I was (see My Story).

Decades of published research shows that both Blastocystis hominis and Dientamoeba fragilis are more common than the parasite Giardia, and accurate diagnosis is dependent on specialised stool collection and testing methods (see side bar). This type of specialised testing is not routinely used when patients present with symptoms of an irritable bowel.

The London School of Tropical Hygiene & Medicine tested chronic IBS patients for parasites using specialised stool collection and staining methods. Forty percent were infected with B.hominis (April 2002. Biomedical Scientist).

In another UK study researchers tested 1,000 IBS patients and again using the same specialsed stool collection and testing methods as above found that 25% were infected with D.fragilis and more than 40% had B.hominis (unpublished data 2000).

The London School of Hygiene & Tropical Medicine consider Blastocystis hominis "may be the most common parasite known to infect humans." (Establishing Cultures of Entamoeba in vitro - on line)

Despite the fact that these parasites are commonly found in those diagnosed with IBS, the majority are not tested for these parasites. This is especially true if the treating physician mistakenly believes parasites are rare in western countries, or that D.fragilis and B.hominis are benign parasites not capable of causing illness.

Two-hundred and twenty-one people diagnosed with IBS responded to a survey on this site.
The question was: "Have you ever been tested for parasitic infection":

IBS symptoms:

Abdominal pain which is relieved after going to the the toilet;
abdominal bloating and discomfort; c
onstipation; periods of diarrhoea;
altered stool form (lumpy, hard , loose, or watery);
alternating constipation and diarrhoea;
need to go to the toilet frequently to defecate or feeling of incomplete emptying of the bowel;
frequent passage of mucus;
altered stool passage (straining, urgency, incomplete evacuation.

D. fragilis symptoms:

Diarrhoea; abdominal pain; abnormal stool (blood with mucus, loose); flatulence, fatigue or weakness; alternating diarrhoea and constipation, constipation, belching; tenesmus (form of constipation); anorexia or malaise. D.Fragilis: A Review with Notes. Yang & Scholten (1976)



TESTING FOR PARASITES

Comprehensive information can be found on the Lab Testing page.