What triggers the acute inflammation and necrosis characteristic of this disorder is unknown; however, Clostridium difficile may produce a toxin that plays a role in its development. The disease typically occurs in patients who are undergoing treatment with broad-spectrum antibiotics or who have received such therapy within the past 4 weeks. Nearly all broadspectrum antibiotics, especially clindamycin, ampicillin, and the cephalosporins, have been linked with its onset. Possible exceptions are vancomycin and aminoglycosides.

Pseudomembranous enterocolitis may also occur postoperatively in debilitated patients undergoing abdominal surgery. Whatever the cause, the necrosed mucosa is replaced by a pseudomembrane filled with staphylococci, leukocytes, mucus, fibrin, and inflammatory cells.

Severe dehydration, electrolyte imbalance, hypotension, shock, colonic perforation, and peritonitis are among the potentially fatal complications associated with this disorder.

The patient’s history usually reveals current or recent antibiotic treatment. Typically, the patient reports the sudden onset of copious, watery or, rarely, bloody diarrhea; abdominal pain; and fever. Palpation may reveal abdominal tenderness.

Careful consideration of the patient history is essential because the abrupt onset of enterocolitis and the emergency situation it creates may make diagnosis difficult.