Background and study aims: The aim of the study was to compare symptoms of Giardia-positive and -negative patients undergoing upper gastrointestinal endoscopy.
Patients and methods: Multi-center questionnaire-based case-control study of 120 Giardia-positive and -negative patients who underwent upper endoscopy. Cases were identified through histological detection of trophozoites of Giardia lamblia in duodenal biopsy specimens. Giardia-negative patients with inconspicuous duodenal histology served as controls.
Results: There was a clear male predominance in the Giardia-positive groups, with 75 cases (62.5 %) being male and 45 (37.5 %) female (P < 0.0001). Giardia-positive cases tended to be older than controls (median 60 years vs. 45.2 years, P < 0.009). The main symptom of positive cases were tenderness to palpation (52.1%), abdominal discomfort (43.3 %), sensation of fullness (40.8%), distension (37.5%), epigastralgia (37.5%), nausea and/or vomiting (35.8%), heartburn (26.7%), and diarrhea (25.8%). Only sensation of fullness (P < 0.02), nausea/vomiting (P < 0.02) and heartburn (P < 0.03) were observed significantly more often in positive cases. Foul-smelling stools, considered typical for giardiasis, were observed in 5.8% of cases. Symptoms lasted for less than 1 month in 28.2 % of cases, for 1-6 months in 35.9%, and for more than 12 months in 35.9% (ns to controls). Treatment resulted in symptomatic cure in 60.5 % and in improvement of symptoms in 21.1 % of cases (P < 0.0001 vs controls).
Conclusion: There are no symptoms that reliably allow the recognition of giardiasis in patients undergoing upper endoscopy.