Pseudomembranous colitis - Gastrointestinal infections

Pseudomembranous colitis

Definition

Pseudomembranous colitis is a form of acute bowel inflammation caused by A and B toxins of Clostridium difficile.

Aetiology/pathophysiology

Usually seen in association with the use of broad-spectrum antibiotics particularly clindamycin. Other implicated antibiotics include ampicillin, tetracycline, cephalosporins. Antibiotics reduce the presence of normal protective bowel flora and allows Clostridium to multiply, causing inflammation and necrosis of bowel mucosa.

Clinical features

Patients (often already hospitalised) develop diarrhoea with variable fever and abdominal cramps. The stools are green, foul smelling and may contain pseudomembranes, fragments of mucosal slough.

Investigations

At sigmoidoscopy the mucosa is erythematous, ulcerated and covered by a membrane-like material.

Identification of the C. difficile toxin in the stool by ELISA is specific and is routinely used.

Culture is possible but usually not required.

Management

The broad-spectrum antibiotics should be stopped and a combination of adequate fluid replacement and oral metronidazole is used. Second-line therapy is with oral vancomycin.