Microbiology Which of the following is the only common pathogenic protozoan found in the duodenum and jejunum? A Entamoeba coli B Balantidium coli C Giardia lamblia D Toxoplasma gondii 💡 Explanation Which of the following is the only common pathogenic protozoan found in the duodenum and jejunum? ✓ Correct Answer: C. Giardia lamblia