Anaerobic spore forming gram positive bacilli, box-car shaped
Nosocomial > community onset diarrhea usually after taking antibiotics.
Can occur in outbreaks.
Recurrence is very common therefore previous history of C. difficile is a risk factor.
Antacids, especially proton-pump inhibitors, and chemotherapy also increase risk.
Wide range of symptoms possible, and 15% are asymptomatic
Profuse, watery diarrhea
Pseudomembranous colitis or toxic megacolon
Normal colonizer in infants
Probiotics may be helpful. In refractory cases, stool transplants have been effective.