II. Definitions

  1. Toxic Megacolon
    1. Rare, life threatening, nonobstructive colon dilation, typically associated with systemic toxicity

III. Causes

  1. Ischemic Bowel
  2. Inflammatory Bowel Disease
    1. Ulcerative Colitis (10% of flares)
    2. Crohn Disease (2.3% of flares)
  3. Infectious Diarrhea
    1. Clostridioides difficile
    2. Salmonella
    3. Shigella
    4. Campylobacter jejuni
    5. Enterohemorrhagic Escherichia coli 0157
    6. Entamoeba histolytica (rare)
    7. Cytomegalovirus (CMV)
      1. CMV (esp. disseminated) is the most common cause of Toxic Megacolon in HIV and AIDS patients

IV. Risk Factors

  1. Hypokalemia
  2. Bowel antimotility agents including Opioids and Anticholinergic Medications
  3. Barium Enema
  4. Colonoscopy preparation

V. Symptoms

  1. Fever and chills
  2. Abdominal Pain
  3. Diarrhea
    1. In contrast, obstipation (complete Constipation) is associated with a worse prognosis

VI. Signs

  1. Abdominal tenderness
  2. Abdominal Distention
  3. Signs of Dehydration and systemic toxicity may be present (e.g. Sinus Tachycardia)

VII. Differential Diagnosis

  1. Hirschprung Disease
  2. Large Bowel Obstruction
  3. Colonic pseudo-obstruction (Ogilvie Syndrome) or other acquired Megacolon
  4. Gastrointestinal dysmotility

VIII. Labs

  1. Complete Blood Count
  2. Comprehensive metabolic panel
  3. Inflammatory markers (e.g. C-RP, ESR)

IX. Imaging

  1. Abdominal XRay
    1. Dilation >6 cm of the transverse colon or ascending colon
  2. Abdominal CT
    1. Colon wall thickening and submucosal edema
    2. Pericolic stranding
    3. Abnormal haustra pattern
    4. Accordion Sign (thick submucosal folds with overlying bands of alternating intensity)
    5. Target Sign (submucosal edema and mucosal hyperemia)

X. Diagnosis: Jalan Criteria

  1. Transverse Colon diameter > 6 cm AND
  2. At least 3 of the following AND
    1. Fever > 101.5 F (38.6 C)
    2. Heart Rate >120 beats/min
    3. White Blood Cell Count > 10.5k/mm3
    4. Anemia
  3. At least 1 of the following
    1. Dehydration
    2. Altered Mental Status
    3. Hypotension
    4. Electrolyte abnormality

XI. Management

  1. Supportive Care
    1. Intravenous Fluids
    2. Correct Electrolyte abnormalities
    3. Withdrawal all medications affecting bowel motility
    4. Bowel rest (keep NPO)
    5. Consider bowel decompression with Nasogastric Tube and rectal tube
  2. Antimicrobials (due to high risk of associated perforation)
    1. Empiric Antibiotics coverage for bowel flora
    2. Screen and treat for Clostridioides difficile
    3. Treat suspected disseminated CMV with gancyclovir
  3. Inflammatory Bowel Disease (esp. Ulcerative Colitis)
    1. Methylprednisolone 60 mg daily for 5 days OR
    2. Hydrocortisone 100 mg every 6 hours
  4. Consult general surgery early in course
    1. Mixed outcomes for early surgical intervention versus medical management
      1. Younger patients may have better outcomes wiith early surgical intervention
      2. D'Amico (2005) Digestion 72(2-3): 146-9 [PubMed]
    2. Indications for surgery
      1. Bowel perforation
      2. Gastrointestinal Hemorrhage
      3. Clinical deterioration
    3. Procedures
      1. Subtotal colectomy and ileostomy (with Hartmann pouch, sigmoidostomy or rectostomy)

XII. Complications

  1. Bowel perforation
  2. Peritonitis
  3. Abdominal Compartment Syndrome

XIII. Prognosis

  1. Mortality is as high as 19% (esp. with bowel perforation)
  2. Mortality rates in Inflammatory Bowel Disease is as low as 0-2% with early management

XIV. Resources

  1. Skomorochow and Pico (2022) Toxic Megacolon, StatPearls,Treasure Island
    1. https://www.ncbi.nlm.nih.gov/books/NBK547679/

XV. References

  1. Kleinmann (2023) Crit Dis Emerg Med 37(2): 22-9
  2. Jalan (1968) Gastroenterology 57(1): 68-82 [PubMed]

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Related Studies

Ontology: Megacolon, Toxic (C0025162)

Definition (MSH) An acute form of MEGACOLON, severe pathological dilatation of the COLON. It is associated with clinical conditions such as ULCERATIVE COLITIS; CROHN DISEASE; AMEBIC DYSENTERY; or CLOSTRIDIUM ENTEROCOLITIS.
Concepts Disease or Syndrome (T047)
MSH D008532
ICD10 K59.3
SnomedCT 28536002
English Megacolon, Toxic, Toxic Megacolon, MEGACOLON TOX, TOX MEGACOLON, Megacolon, Toxic [Disease/Finding], toxic megacolon, Toxic megacolon, Acute megacolon, Toxic dilatation of colon, Toxic megacolon (disorder), megacolon; toxic, toxic; megacolon, Megacolon toxic
Dutch toxische dilatatie van colon, toxisch megacolon, megacolon; toxisch, toxisch; megacolon, Megacolon, toxisch, Toxisch megacolon
German Megakolon toxisch, toxisch bedingte Dilatation des Kolons, Megakolon, toxisches, Toxisches Megakolon
Italian Dilatazione tossica del colon, Megacolon tossico
Portuguese Dilatação tóxica do cólon, Megacólon tóxico, Megacólon Tóxico, Megacolo Tóxico
Spanish Dilatación tóxica del colon, Megacolon tóxico, dilatación tóxica del colon, megacolon agudo, megacolon tóxico (trastorno), megacolon tóxico, Megacolon Tóxico
Japanese 中毒性結腸拡張, チュウドクセイケッチョウカクチョウ, チュウドクセイキョダイケッチョウ, 巨大結腸-中毒性, 中毒性巨大結腸, 中毒性巨大結腸症, 巨大中毒性結腸症, 結腸症-巨大中毒性
Swedish Megakolon, toxisk
Czech megakolon toxické, Toxická dilatace tračníku, Toxické megakolon
Finnish Toksinen megakoolon
Russian MEGAKOLON TOKSICHESKII, МЕГАКОЛОН ТОКСИЧЕСКИЙ
Polish Rozszerzenie okrężnicy toksyczne
Hungarian Megacolon, toxikus, Vastagbél toxikus tágulata
Norwegian Toksisk megakolon, Toksisk megacolon
French Mégacôlon toxique