22nd July 2023

A 73-year-old man is in the intensive care unit having undergone triple coronary artery bypass graft surgery

A 73-year-old man is in the intensive care unit having undergone triple coronary artery bypass graft surgery for complex triple vessel coronary disease 3 days ago without complications. He has a history of angina, hypertension and hyperlipidaemia. His medications include bisoprolol 2.5mg OD, ramipril 5mg OD, aspirin 75mg OD, ticagrelor 90mg BD and atorvastatin 80mg ON. He now complains of cramping left-sided abdominal pain which worsens during the day. He is tender in his left iliac fossa and on the PR exam there is bloody stool. His stool chart reveals five type 7 stools since the day before. An urgent CT abdomen and pelvis with contrast is arranged which shows evidence of ischaemic colitis.

Given the most likely diagnosis, which portion of the bowel is most likely to be affected?

Select the SINGLE most appropriate option from the list below. Select ONE option only.