PARASITES & OTHER ILLNESS: Chronic Fatigue Syndrome: AfME member Sarah Thompson asks whether gut parasites could be preventing some of us from getting better. Colitis: Blastocystis hominis complicating ulcerative colitis The response of our patient to metronidazole therapy raises the possibility that other ulcerative colitis patients might benefit from this treatment and so postpone or avoid the need for major surgery. We would suggest the examination of stool specimens, looking specifically for this organism be performed routinely in ulcerative colitis patients with refractory symptoms. J.of the Royal Soc. of Med (Vol 84 Oct. 91) Presumptive evidence for Blastocystis hominis as a cause of colitis. A patient with persistent diarrhea was found to have biopsy-proved colitis with large numbers of the protozoan Blastocystis hominis present in stool. Extensive evaluation failed to reveal any other potential etiologic agent of acute colitis. Following treatment with a course of metronidazole, the patient became asymptomatic, B hominis was no longer present in stool, and results of a repeated biopsy were normal. These observations are consistent with the role of B hominis as a gastrointestinal pathogen. Arch Intern Med 1988 May;148(5):1064 The following e-mail was sent by the parents of a child who tested positive for Blastocystis hominis: "Your site was very helpful to us for another reason however. Our 16 year old son who was perfectly well went to camp about a year ago and returned with bloody mucusy diarrhea. He eventually lost 30 pounds and had a lengthy hospitalization. WE TRULY BELIEVED IT WAS A PARASITIC SITUATION DUE TO ITS ABSOLUTE ABRUPT ONSET. Doctors were quick to diagnose Ulcerative colitis at great expense." L. Jan 02 DIENTAMOEBA & COLITIS: Clinical reports have suggested that Dientamoeba fragilis may be a cause of acute and chronic colitis in children and adults. The mechanism by which this parasite process produces colitis has not been determined. The clinical findings of this report suggest that D.fragilis causes colitis through an invasive ulcerating process. Shein R. Gelb.A. Colitis due to dientamoeba fragilis. Am. J Gastroenterol. 1983; 78(10): 634-6 D Fragilis is thought to inhabit the mucosal crypts of the large intestine (1). Although it is considered to be non-invasive one case of colitis attributed to this organism has been reported (2). (1) Markell E.K, Voge M, Medical parasitology, 5th ed. Philadelphia: Saunders 1981; 61-63 (2) Shein R, Gelb A. Colitis due to dientamoeba fragilis. Am.J.Gastroenterology 1983; 78: 634-6 Dientamoeba fragiis: a bowel pathogen? Robert Oxner et al. New Zealand Medical Journal. 11 Feb. 87 Dientamoeba fragilis is a rare cause of chronic infectious diarrhoea and colitis in children......Eosinophilic colitis documented by colonoscopy, was due to D. fragilis..... CONCLUSIONS: D. fragilis should be included in the differential diagnosis of chronic diarrhoea and eosinophilic colitis. Dientamoeba fragilis masquerading as allergic colitis. Cuffari C, Oligny L, Seidman EG Department of Pediatrics, Hopital Sainte-Justine, Universite de Montreal, Canada J Pediatr Gastroenterol Nutr 1998 Jan;26(1):16-20 . Eur J Pediatr 1997 Jul;156(7):583