Multiple choice Which of the following is not a causative agent of diarrhoea? Escherichia coli Entamoeba Rotavirus Ascaris Salmonella Reveal answer Fill a bubble to check yourself D Correct answer Explanation This is the correct option as salmonella causes typhoid. Ascariasis is an infection of the small intestine caused by Ascaris lumbricoides (A. lumbricoides), which is a species of roundworm.