Toxic megacolon

Acute form of colonic distension

Toxic megacolon is a severe complication of colitis, characterized by an extreme dilation of the colon. This condition can lead to perforation, sepsis, and can be life-threatening if not treated promptly. It is most commonly associated with inflammatory bowel diseases such as ulcerative colitis and Crohn's disease, as well as infections like Clostridioides difficile colitis.

Pathophysiology

Toxic megacolon occurs when inflammation extends into the muscular layers of the colon, leading to paralysis of the colonic muscles. This results in the inability of the colon to contract and move its contents, causing massive dilation. The dilation can lead to increased pressure within the colon, which may result in perforation.

Toxic megacolon in a patient with ulcerative colitis

Causes

The primary causes of toxic megacolon include:

• Ulcerative colitis
• Crohn's disease
• Clostridioides difficile infection
• Ischemic colitis
• Infectious colitis from other pathogens

Symptoms

Symptoms of toxic megacolon include:

• Severe abdominal pain and distension
• Fever
• Tachycardia
• Dehydration
• Shock

Diagnosis

Diagnosis of toxic megacolon is typically made based on clinical presentation and imaging studies. An abdominal X-ray or CT scan can reveal the extent of colonic dilation. Laboratory tests may show signs of infection or inflammation.

Surgical specimen showing toxic megacolon

Treatment

Treatment of toxic megacolon involves:

• Bowel rest and nasogastric decompression
• Intravenous fluids and electrolytes
• Broad-spectrum antibiotics
• Corticosteroids for inflammatory bowel disease
• Surgery, such as colectomy, if there is no improvement or if perforation occurs

Prognosis

The prognosis of toxic megacolon depends on the underlying cause and the timeliness of treatment. Early recognition and management are crucial to prevent complications such as perforation and sepsis.

Prevention

Preventive measures include:

• Effective management of underlying inflammatory bowel diseases
• Prompt treatment of colonic infections
• Regular monitoring for patients at risk

Pseudomembranes in the colon, often associated with Clostridioides difficile infection

Related pages

• Ulcerative colitis
• Crohn's disease
• Clostridioides difficile
• Inflammatory bowel disease