26th April 2024

A 70-year-old man presents with a 2-day history of intermittent, crampy left lower quadrant abdominal pain.

A 70-year-old man presents with a 2-day history of intermittent, crampy left lower quadrant abdominal pain. He also reports a recent change in his bowel habits, with episodes of constipation alternating with diarrhoea. He denies any rectal bleeding, weight loss, or fever. His past medical history is significant for hypertension, and his medications include amlodipine and a daily aspirin.

On examination, his abdomen is soft with mild tenderness in the left lower quadrant. There is no rebound tenderness, guarding, or palpable masses. Rectal examination is normal with no blood noted.

Investigations:

Complete blood count: Normal

Abdominal CT scan: Thickening of the sigmoid colon wall with surrounding fat stranding, no abscess or perforation

Stool guaiac test: Negative

C-reactive protein: Mildly elevated

Which is the most likely diagnosis?