Potential impact of colonic irrigation on the indigenous intestinal microflora

Under normal physiological conditions, the indigenous intestinal microflora is stable. The stability protects the host from colonization of nonindigenous microorganisms, including pathogens. Indigenous microorganisms capable of producing toxins are held in check by competing microflora, but any accidentally absorbed toxins are efficiently detoxified by the liver in the absence of hepatic pathology. Antibiotics are known to disrupt the normal flora leading to increased susceptibility to infection with other members of the normal flora or to toxins produced by them. It is possible that mechanical disruption of the flora by colonic irrigation could have a similar effect. Inadequately disinfected colonic irrigation machines have been the source of documented iatrogenic infection with Entamoeba histolytica. The potential for iatrogenic transmission of AIDS in a similar fashion must be considered.