Colitis, Antibiotic-Associated

• • Results from antibiotic therapy or alteration in colonic flora

  • Diarrhea with or without gross mucosal abnormalities

  • Caused by Clostridium difficile toxins A and B

  • Also referred to as pseudomembranous colitis

  • Clindamycin, ampicillin, cephalosporins are common inciting antibiotics

  • May progress to toxic megacolon, perforation

  • Symptoms may develop up to 6 weeks following antibiotic treatment

Epidemiology

• • Transmitted in hospital or closed environments

  • Epidemics noted on surgical wards

  • Can be transmitted by health care personnel, making wearing gloves and washing hands essential

  • Infection can be especially severe in immunocompromised patients

Symptoms and Signs

• • Watery, green diarrhea, sometimes bloody

  • Crampy abdominal pain, cramping

  • Vomiting

  • Fever

  • Complications including toxic megacolon or perforation may lead to peritoneal signs

Laboratory Findings

• • Leukocytosis

  • Positive tests for C difficile cytotoxin

  • Positive stool culture

Imaging Findings

• • Endoscopy (sigmoidoscopy)

  • -Elevated plaques

    -Pseudomembranes

    -Erythematous, edematous mucosa

  • Biopsy

  • -Leukocytes

    -Necrotic epithelium

    -Fibrin

• • Malignancy

  • Stricture

  • Ischemic colitis

  • Diverticulitis

Rule Out

• • Other causes of infectious colitis

  • -Amebic

    -Actinomycosis

    -Cytomegalovirus (in immunocompromised patients)

• • Sigmoidoscopy/colonoscopy with or without biopsy

  • Stool culture, C difficile cytotoxin

  • WBC count

  • History of antibiotic therapy

When to Admit

• • Dehydration

  • Worsening abdominal pain/distention

• • Discontinue inciting antibiotic

  • Oral vancomycin for 7-10 days

  • Oral metronidazole for 7-14 days

  • Avoid antidiarrheal medications

Surgery

Indications

• • Failure of medical management with worsening clinical course/progression to toxic megacolon, peritonitis, perforation

Medications

• • Oral vancomycin

  • Oral metronidazole

Treatment Monitoring

• • Serial abdominal exams

  • Serial WBC count

Complications

• • Sepsis

  • Colonic dilatation, perforation

  • Hypovolemia/shock

Prognosis

• • Recurrence after treatment is 20%

Prevention

• • Proper hand washing and protective barrier (gown and gloves) with infected patients

  • Discontinue unnecessary antibiotics

References