A 72-year-old woman presents with sudden 3-day history of bright red rectal bleeding and a history of diverticular disease. She has a low ejection fraction and hypotension but is afebrile. Which diagnosis is most likely?

• A. Ischemic colitis
• B. Acute diverticulitis
• C. Bowel perforation
• D. Hemorrhoids

Answer: (A)

Ischemic colitis results from reduced blood flow to the colon in a low-perfusion state, which is common in older patients with cardiac dysfunction or hypotension. When mesenteric blood flow drops, the colonic mucosa becomes ischemic and bleeds, often presenting as sudden lower GI bleeding in the setting of vascular disease or shock. In this scenario, the patient is elderly with a history of diverticular disease and has hypotension with a low ejection fraction, making a low-flow–related mucosal injury the most plausible cause of bright red rectal bleeding.

Diverticulitis would more likely cause localized left lower quadrant pain with fever and leukocytosis. Bowel perforation presents with acute, severe abdominal pain and signs of peritonitis. Hemorrhoids typically cause painless bleeding without systemic signs such as hypotension.