Clostridium difficile infection
	Constipation-predominant IBS
	Diarrhoea-predominant IBS
	Colitis

Although the cause of IBS is unknown it has been termed "a functional disorder" because there is no sign of any disease when the bowels are examined (normal structure) and it is presumed that only the function has changed. The condition can cause a great deal of discomfort with some patients eventually knowing where every toilet/bathroom is located between home and work. Some patients have episodes of incontinence and yet, the disease continues to be explained by psychogenic factors, with visceral hypersensitivity, neurotransmitter imbalance and stress or fibre deficiency. Recently, infection and inflammation has been obliquely alluded to as a possible cause.^20-22

Observations showing that many patients develop diarrhoea-predominant IBS following a gastrointestinal infection or the use of antibiotics, that metronidazole and other antibiotics can transiently suppress the symptoms,²³ and that symptoms can be totally reversed by HPI in many patients, ^{7, 24} have led to the suggestion that diarrhoea-predominant IBS is also a chronic infection that has not been detected by standard stool tests. It needs to be remembered that the majority of chronic diarrhoeal infections are caused by agents yet to be defined by scientific endeavour. This concept can be more easily understood by the fact that for over 70 years the cause of chronic peptic ulcer disease was blamed on stress and high acid output while at the same time Helicobacter pylori was visible under the microscope but not recognised as the cause of ulcer disease. Chronic IBS is also likely to be shown to be caused by a number of infective agents since all clinical and pathologic findings point to this very fact. Indeed, in retrospect, it is much easier to imagine IBS to be caused by infections of the bowel flora than it was to believe that peptic ulcers could be caused by a chronic gastric infection.

However, patients with diarrhoea-predominant IBS need first to be investigated for known infective pathogens, especially parasites and C. difficile. This is best achieved by obtaining a sample of stool at initial colonoscopy rather than using a normal stool sample. In this way a 'purged' specimen is obtained in a very fresh state and immediately placed in the appropriate fixative to maximise detection of the offending bugs. At PTRC patients are first investigated via colonoscopy and aspirated fluid from the caecum is collected. Particular attention is given to collection of stool specimens in SAF (sodium acetate, acetic acid, and formalin) fixative especially for diagnosis of Dientamoeba fragilis, Blastocystis hominis, Entamoeba histolytica, other rare parasites, C. difficile and its toxin, Aeromonas hydrophilia, C. jejuni and other pathogens. The bacteria are cultured from unfixed specimen. Once parasitic diseases have been cured and no other pathology is seen such as chronic colitis, polyps, cancer or Crohn's disease, the patient will be ready for probiotic infusion originating from a human source (HPI). In diarrhoea-predominant IBS it is hypothesised that a yet undescribed or undetectable bacterial species causing chronic infection - also probably a clostridium-type bacterium - is secreting toxins that influence the bowel enteric nerves in several ways. They can induce water secretion from the bowel causing the diarrhoea, stimulate pain fibres resulting in cramping pain and the bacteria can manufacture gas causing excessive flatulence. Lavage or purging of the bowel prior to infusion of normal flora from another human being allows for removal of the majority of pathogenic bacteria while allowing the incoming human flora to act as a powerful antibiotic7 to combat the remaining pathogens and also to bring in any missing components of the flora to implant in the bowel wall of the recipient who has been suffering with IBS. It should be noted that commercially available oral probiotics are incapable of implanting permanently in the gut flora as they have lost their capability to adhere to epithelial cells through the process of culturing in the commercial laboratory. It is only fresh human probiotic from another human being that retain that capability and hence can be implanted long term.