Giardia lamblia in patients undergoing endoscopy: lack of evidence for a role in nonulcer dyspepsia.

Previous studies have suggested that Giardia lamblia may cause nonulcer dyspepsia as the sole manifestation of infection. To explore this premise, duodenal aspirates from patients undergoing upper endoscopy were examined for Giardia and results were correlated with endoscopic findings and symptoms. Of 155 patients, 15.5% had Giardia. Patients with dyspepsia, with or without obvious lesions at endoscopy, had a similar prevalence. Patients with vomiting and diarrhea had an increased prevalence (38.5%) (p less than 0.05). The prevalence of Giardia lamblia in this patient population is surprisingly high. This study suggests that Giardia lamblia infection is not a major cause of nonulcer dyspepsia.