Patient will present as → a 33-year-old male with a known history of ulcerative colitis presents to the emergency department with severe abdominal pain, diarrhea, and a fever of 103.2°F that began two days ago. He notes that his diarrhea has recently worsened, and he has been passing several bloody stools daily. He also reports significant abdominal distension. On examination, he is tachycardic and hypotensive, with a distended, tender abdomen and reduced bowel sounds. His white blood cell count is markedly elevated, and a plain abdominal X-ray reveals colonic dilation of 7.5 cm. You suspect toxic megacolon. He is admitted to the intensive care unit for close monitoring and immediate medical management. A surgical consult is obtained. Intravenous corticosteroids are started to reduce inflammation, and broad-spectrum antibiotics are initiated to cover secondary infections. Fluid resuscitation is given to correct dehydration and electrolyte imbalances.
Toxic megacolon is usually a complication of inflammatory bowel disease, such as ulcerative colitis and, more rarely, Crohn's disease, and of some infections of the colon, including Clostridium difficile infections, which have led to pseudomembranous colitis.
- Life-threatening form of colon distention
- Patients will present with FEVER, markedly distended abdomen with peritonitis and shock
- KUB shows a dilated colon > 6 cm
- Common in patients with Ulcerative Colitis and Crohn's disease
Toxic megacolon is diagnosed based on clinical signs of systemic toxicity combined with radiographic evidence of colonic dilatation (diameter >6 cm)
- Radiographic evidence of colonic distension
- PLUS at least three of the following:
- Fever >38ºC
- Heart rate >120 beats/min
- Neutrophilic leukocytosis >10,500/microL
- Anemia
- PLUS at least one of the following:
- Dehydration
- Altered sensorium
- Electrolyte disturbances
- Hypotension
Supportive therapy for all patients with toxic megacolon includes ICU monitoring, fluid resuscitation, broad-spectrum antibiotics, bowel rest, and surgical consultation
- Bowel decompression with a nasogastric tube can be performed at the discretion of the treating clinician
Definitive Therapy for IBD-Related Toxic Megacolon:
-
- IV glucocorticoid therapy for three days.
- Infliximab (preferred) or cyclosporine (alternative for UC only) for three days if there is no response to glucocorticoids
- Subtotal colectomy and ileostomy if the patient does not respond to medical treatment or develops toxic megacolon despite glucocorticoid, infliximab, or cyclosporine therapy
- IV glucocorticoid therapy for three days.
Definitive Therapy for C. difficile-Related Toxic Megacolon:
-
- Antibiotic therapy targeted to C. difficile infection
- Surgery indicated if colonic perforation, necrosis, ischemia, compartment syndrome, peritonitis, or end-organ failure, with options for total abdominal colectomy or diverting ileostomy with colonic lavage.
Question 1 |
Hirschsprung’s disease Hint: presents with chronic constipation. Patients are not usually toxic except when intestinal perforation occurs. | |
Cytomegalovirus colitis Hint: Occurs in immunocompromised persons. | |
Toxic megacolon | |
Kaposi’s sarcoma Hint: Occurs in immunocompromised persons. |
Question 2 |
Radiographic evidence of colonic dilatation (>6cm) Hint: See C for explanation | |
Fever (>101.50F) Hint: See C for explanation | |
Blood pressure > 150/90 | |
Heart rate > 120/min Hint: See C for explanation |
Question 3 |
Ulcerative colitis Hint: See B for explanation | |
Pancreatitis | |
Crohn colitis Hint: See B for explanation | |
Pseudomembranous colitis Hint: See B for explanation |
Question 4 |
Dilated colon (>6 cm). Hint: See C for explanation | |
Loss of colonic haustrations. Hint: See C for explanation | |
Frimann Dahl sign. | |
Segmental colonic parietal thinning. Hint: See C for explanation |
Question 5 |
Placing of intravenous line for rehydration and electrolyte correction. Hint: See D for explanation | |
Administration of broad spectrum intravenous antibiotics. Hint: See D for explanation | |
Passage of a nasogastric tube for decompression. Hint: See D for explanation | |
Administration of an antidiarrheal agent. |
List |
References: Merck Manual · UpToDate