Toxic megacolon is a life-threatening complication of other intestinal conditions, characterized by a very dilated colon, abdominal distention, and sometimes fever, abdominal pain, or shock.

Alternative Names

Toxic dilation of the colon; Megarectum

Causes, incidence, and risk factors

This is a complication of inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease , and some infections of the colon. Other forms of megacolon exist and can be congenital (from birth) or associated with some forms of constipation.

Signs and tests

There may be signs of

septic shock . A physical examination reveals abdominal tenderness and possible loss of bowel sounds .

An

abdominal film shows colonic dilation.

A

CBC may possibly show an elevated white blood cell count .

Blood electrolytes may show a low potassium level or signs of dehydration.

Treatment

The objective of treatment is to decompress the bowel and pass an intestinal tube to prevent swallowed air from further distending the bowel. If decompression is not achieved or the patient does not improve, often within 24 hours, a colectomy (surgical resection of a portion or all of the colon) is indicated. Fluid and electrolyte replacement help to prevent dehydration and shock . Use of corticosteroids may be indicated to suppress the inflammatory reaction in the colon if the megacolon has resulted from active inflammatory bowel disease. Antibiotics may be given to prevent sepsis (a severe infection).

Expectations (prognosis)

If the condition does not improve, there is a significant risk of death. In this situation, a colectomy is usually required.

Complications

Sepsis

Shock

Perforation of the colon

Calling your health care provider

Go to the emergency room or call the local emergency number (such as 911) if severe abdominal pain develops -- particularly if it is accompanied by fever , rapid pulse ( heart rate ), tenderness when the abdomen is gently pressed, or other symptoms, such as bloody diarrhea, frequent diarrhea , or painful bowel movements.

Prevention

Treatment of the underlying disease is important in preventing toxic megacolon.