A 63-year-old man develops watery diarrhoea 8 times per day with lower abdominal cramps 5 days after completing a course of Co-amoxiclav for pneumonia. He is afebrile and haemodynamically stable. What is the most appropriate initial investigation?AColonoscopy with biopsiesBStool microscopy for ova, cysts and parasitesCStool culture for Salmonella and Shigella onlyDStool Clostridioides difficile toxin assayECT abdomen and pelvis with contrastCheck my answer