Explosive

A 35 year old man presents with watery diarrhea and nausea for 4 weeks.

During this time, his bowel movements changed from once a day to 4 to 6 times a day with foul smelling, loose, urgent stools associated with a crampy abdominal pain.

He had lost 8 kg of weight during the same time period.

The symptoms started around 1 week after returning from a holiday to Turkey, where he had gone camping and drunk water from a natural spring.

His medical and surgical histories are unremarkable but his family history is significant for a sister with celiac disease.

Select Relevant Investigations
Stool Microscopy

Performed

Fresh stool examination for leucocytes, erythrocytes and trophozoites is negative.
Fixed stool examination for enteric parasites is negative.
Routine stool examination for enteric parasites is negative.
Stool Culture and Antigen Assay

Performed

Positive for Giardia.
Negative for routine bacteria, rotavirus/adenovirus antigen and Clostridium difficile antigen.
The Cryptosporidium antigen is not detected by a Lateral Flow Test (LFT).
Serology for Gluten Antibodies

Performed

EMA (Immunoglobulin A anti-endomysium antibodies): negative
AGA (IgA anti-gliadin antibodies): negative
tTGA (IgA anti-tissue transglutaminase): negative
Endoscopy & Duodenal Biopsy

Performed

No macroscopic features suggestive of celiac disease.
Biopsies indicated partial villous atrophy.
No crypt hyperplasia or intraepithelial lymphocytes.
Heavy colonization with G. lamblia trophozoites noted.

Select Relevant Management
Metronidazole
Gluten Free Diet
Health Education
Isolation