Toxic megacolon

Background

• Inflammation of intestinal smooth muscle causes colon dilation
• Untreated, can lead to perforation
• Usually associated with infectious colitis or Crohn's disease or Ulcerative Colitis
• Triggers:
  • Anti-motility agents
  • Anticholinergics
  • Narcotics
  • Pregnancy
  • Enemas
  • Recent colonoscopy

Clinical Features

• Abdominal Pain
• Fever
• Tachycardia
• Diarrhea
• Distended abdomen
• Hypokalemia
• Hypomagnesemia
• Perforation
  • Peritonitis
  • Septicemia

Differential Diagnosis

• Small bowel obstruction
• Large Bowel Obstruction
• Constipation
• C. difficile colitis

Diagnosis

• X-ray showing colon > 6 cm diameter
  • Can also see loss of haustra, "thumb-printing" (bowel edema)
• Labs:
  • leukocytosis
  • electrolyte disturbances
  • anemia
  • hypoalbuminemia

Management

• Fluid hydration
• IV corticosteroids
• Antibiotics to cover bowel flora
  • Mild to moderate disease
    • ciprofloxacin 400 mg IV q12h AND metronidazole 1 g IV q12h
    • ticarcillin-clavulanate 3.1 g IV q6h
  • Severe disease
    • ampicillin 2 g IV q6h AND metronidazole 500 mg IV q6h AND gentamicin 7mg/kg q24h
    • Imipenem 500 mg IV q6h
• Early surgical consultation if no improvement in 24-48 hours

Disposition

• Admit

See Also

Crohn's disease Ulcerative Colitis