Patients with Clostridium difficile infection and prior appendectomy may be prone to worse outcomes

Table 1 Classification of Clostridium difficile infection severity based on the Infectious Diseases Society of America criteria

Severity	IDSA criteria
Mild	WBC < 15 × 109/L and serum creatinine < 1.5 times premorbid level
Severe	WBC ≥ 15 × 109/L, or serum creatinine ≥ 1.5 times premorbid level
Fulminant (severe, complicated)	Hypotension, shock, ileus, or megacolon

IDSA: Infectious Diseases Society of America; WBC: White blood cell.