Toxic megacolon

Background

• Acute colonic distension that can lead to perforation and death

Etiology

• Inflammatory bowel disease
  • Ulcerative colitis is most common
  • Crohn disease, rarely
• Gastrointestinal infection
  • Clostridioides difficile
  • Entamoeba histolytica
  • Shigella
• Congenital
  • Hirschsprung disease

Clinical Manifestations

• Abdominal pain
• Signs of sepsis
  • Fever
  • Hypotension
  • Shock
• Signs of IBD (usually ulcerative colitis)
• May be first presentation of IBD

Investigations

• Imaging:
  • Abdominal X-ray will show colon dilated > 6cm

Diagnosis

• Radiographic evidence of colonic distension
• Plus at least three of:
  • Fever > 38ºC
  • Heart rate > 120bpm
  • WBC > 10.5
  • Anemia
• Plus at least one of:
  • Volume depletion
  • Altered sensorium
  • Electrolyte abnormalities
  • Hypotension

Management

• Conservative
  • Bowel rest, NG tube
  • If IBD: steroids
  • If infectious: antibiotics
• If conservative treatment fails, proceed to surgery for subtotal colectomy and end-ileostomy