Toxic megacolon

Toxic megacolon is an acute form of colonic distension.

• Abdominal bloating
• Abdominal pain
• Abdominal tenderness
• Dehydration
• Fever
• Tachycardia (rapid heart rate)

There may be signs of septic shock. A physical examination reveals abdominal tenderness and possible loss of bowel sounds. An abdominal radiography shows colonic dilation. White blood cell count is usually elevated. Severe sepsis may present with hypothermia or leukopenia.^{[citation needed]}

Complications

• Perforation of the colon^[3]
• Sepsis
• Shock

Emergency action may be required if severe abdominal pain develops, particularly if it is accompanied by fever, rapid heart rate, tenderness when the abdomen is pressed, bloody diarrhea, frequent diarrhea, or painful bowel movements.

Colonoscopy is contraindicated, as it may rupture the dilated colon resulting in peritonitis and septic shock.

Pathophysiology

The pathological process involves inflammation and damage to the colonic wall with unknown toxins breaking down the protective mucosal barrier and exposing the muscularis propria.^[4] There is relative destruction of the ganglion cells and swelling of the nerve fibers in the myenteric plexus, with concomitant damage to the colonic musculature.^[4] This results in almost complete paralysis of the diseased segment of the colon with loss of smooth muscle substance, tone and motility.^[4] This can lead to further complications as pressure builds up in the colon due to relative fecal stasis including sepsis, intestinal hemorrhage or free perforation and spontaneous decompression.^[4]

Diagnosis

Massively dilated colon with air-fluid level can be seen on abdominal radiograph or CT scan.^[5][6]

Treatment

The objective of treatment is to decompress the bowel and to prevent swallowed air from further distending the bowel. If decompression is not achieved or the patient does not improve with medical management, surgery is indicated. When surgery is required the recommended procedure is a

If the condition does not improve, the risk of death is significant. In case of poor response to conservative therapy, a colectomy is usually required.[9]

References