Dientamoeba Fragilis: A Neglected Parasitic Cause of Chronic Colitis

<i>Dientamoeba fragilis</i> is a protozoan parasite whose pathogenicity remains unclear due to limited evidence and contradictory study results. We present a case of a 36-year-old woman with chronic gastrointestinal symptoms with an elevated fecal calprotectin who had endoscopic findings of patchy left-sided colitis, which persisted on interval colonoscopy 6 months later. Diagnosis was delayed due to 2 initial negative polymerase chain reactions before a positive result. The patient's symptoms and endoscopic findings resolved after microbiological clearance of <i>Dientamoeba fragilis</i> with paromomycin. We highlight the difficulties in diagnosing this condition and make a case for its pathogenicity.