Question

Regarding pseudomembranous colitis, all of the following are true except?

• A. Toxin A is responsible for the clinical manifestations
• B. Toxin B is responsible for the clinical manifestations
• C. Blood in stools is a common feature
• D. Summit lesions are an early histopathological finding

Hint:

This C. difficile disease causes watery, not bloody, diarrhoea; spot the false statement.

Answer 1

The Correct Option is C

Step 1: Pseudomembranous colitis is caused by Clostridioides difficile (formerly Clostridium difficile), usually after antibiotic use that disturbs the normal gut flora. It produces two toxins, toxin A (enterotoxin) and toxin B (cytotoxin), both of which contribute to the clinical disease, so options a and b are true.

Step 2: The classic early histopathological finding is the summit (volcano) lesion, where a focal exudate of fibrin and inflammatory cells erupts from the mucosal surface, so option d is true.

Step 3: The typical presentation is profuse watery diarrhoea with crampy abdominal pain. Grossly bloody diarrhoea is NOT a common feature of pseudomembranous colitis. This is the false statement and therefore the answer to this except question.

Step 4: Because blood in stools is uncharacteristic, option c is the exception and is the correct choice.