Introduction: Dientamoeba fragilis (DF) is a commonly occurring intestinal protozoan that is
considered a possible cause of infectious gastrointestinal disease in adults and children. DF
has a particular high prevalence in children, and it is suspected that children present more
symptoms in infection than adults. However, evidence of causality is lacking, treatment
regimens are largely untested in controlled trials, and the most commonly used antibiotic
against DF in Denmark, metronidazole, has never been tested against placebo.
Main objective: To determine the clinical effect of metronidazole in DF-infected children
with gastrointestinal complaints, where no other aetiology is known and no other
gastrointestinal pathogens could be shown.