Symptomatic giardiasis without diarrhea: further evidence to support the routine duodenal biopsy?

Gastrointest Endosc. 2003 Jul;58(1):120-2. doi: 10.1067/mge.2003.199.


Background: Worldwide, Giardia lamblia is the most common protozoan isolated from the GI tract. Patients with symptoms caused by giardiasis typically present with diarrhea, the absence of which may result in a low clinical index of suspicion for the diagnosis.

Methods: A series of 6 patients with giardiasis presenting without diarrhea is reported. Five presented with atypical GI symptoms. In all 6 cases, diarrhea was absent. Upper GI pathology was suspected by the investigating clinician and EGD was therefore arranged.

Observations: Five of the 6 patients improved with appropriate antibiotic treatment.

Conclusion: This series of cases demonstrates the importance of considering G lamblia as a cause for GI symptoms even in the absence of diarrhea. Routine procurement of duodenal biopsy specimens is valuable for recognition of atypical presentations of patients with G lamblia and avoiding delays in diagnosis.

MeSH terms

  • Adult
  • Animals
  • Biopsy, Needle
  • Diarrhea
  • Duodenum / pathology*
  • Endoscopy, Gastrointestinal / methods
  • Female
  • Follow-Up Studies
  • Giardia lamblia / isolation & purification*
  • Giardiasis / diagnosis*
  • Giardiasis / drug therapy
  • Humans
  • Immunohistochemistry
  • Male
  • Metronidazole / administration & dosage
  • Middle Aged
  • Risk Assessment
  • Sampling Studies
  • Severity of Illness Index
  • Treatment Outcome


  • Metronidazole