A young girl returns from a trip to India with a protracted history of watery diarrhoea.
Giardiasis is suspected but three stool samples are negative.
What is the best investigation to confirm Giardia as a diagnosis?
a) CT abdomen
b) Rectal biopsy
c) Serum IgM Giardia antibodies
d) Small intestine biopsy
e) Stool microscopy
Answer