Clostridioides difficile , previously Clostridium difficile, is a common bacterial cause of diarrhea in multiple species including suckling piglets. C. difficle is a spore-forming, obligate anaerobe; characteristics that are important in the pathogenesis of C. difficile associated disease (CDAD) in neonatal pigs.

Once inside the gastrointestinal tract, particularly the colon, the pathogenesis of CDAD is connected to spore germination and toxin production that injure the colonic epithelium.