<prompt> A patient presented with complains of chronic constipation and diarrhoea. There was excessive associated weight loss. Intestinal biopsy was obtained and it showed the following findings. What is your diagnosis?GiardiaEntamoebaWhipples diseaseCMV  <response>: Ans. a Giardia This image shows Giardia lamblia infection of the small intestine. The small pear-shaped trophozoites live in the duodenum and become infective cysts that are excreted. They produce a watery diarrhea. A useful test for diagnosis of infectious diarrheas is stool examination for ova and parasites. 