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Toxic Megacolon

What is toxic megacolon?

The large intestine is the lowest section of your digestive tract. It includes your appendix, colon, and rectum. The large intestine completes the digestive process by absorbing water and passing waste (stool) to the anus.

Certain conditions can cause the large intestine to malfunction. One such condition is toxic megacolon or megarectum. Megacolon is a general term that means the abnormal dilation of the colon. Toxic megacolon is a term used to express the seriousness of the condition.

Toxic megacolon is rare. It’s a widening of the large intestine that develops within a few days and can be life-threatening. It can be a complication of inflammatory bowel disease (such as Crohn’s disease).

What causes toxic megacolon?

One of the causes of toxic megacolon is an inflammatory bowel disease (IBD). Inflammatory bowel diseases cause swelling and irritation in parts of your digestive tract. These diseases can be painful and cause permanent damage to your large and small intestines. Examples of IBDs are ulcerative colitis and Crohn’s disease. Toxic megacolon can also be caused by infections such as Clostridium difficile colitis.

Toxic megacolon occurs when inflammatory bowel diseases cause the colon to expand, dilate, and distend. When this happens, the colon is unable to remove gas or feces from the body. If gas and feces build up in the colon, your large intestine may eventually rupture.

Rupture of your colon is life-threatening. If your intestines rupture, bacteria that are normally present in your intestine release into your abdomen. This can cause a serious infection and even death.

It’s important to note that there are other types of megacolon. Examples include:

  • pseudo-obstruction megacolon
  • colonic ileus megacolon
  • congenital colonic dilation

Although these conditions can expand and damage the colon, they’re not due to inflammation or infection.

What are the symptoms of toxic megacolon?

When toxic megacolon occurs, the large intestines rapidly expand. Symptoms of the condition may come on suddenly and include:

Toxic megacolon is a life-threatening condition. If these symptoms develop, you should seek immediate medical attention.

How is toxic megacolon diagnosed?

If you develop symptoms of toxic megacolon, your doctor can confirm your diagnosis through a physical exam and other tests. They will ask you about your health history and whether you have an IBD. Your doctor will also check to see if you have a tender abdomen and if they can hear bowel sounds through a stethoscope placed on your abdomen.

If your doctor suspects that you have toxic megacolon, they may order more tests. Additional tests to confirm this diagnosis include:

How is toxic megacolon treated?

The treatment of toxic megacolon usually involves surgery. If you develop this condition, you will be admitted to the hospital. You will receive fluids to prevent shock. Shock is a life-threatening condition that occurs when an infection in the body causes your blood pressure to decrease rapidly.

Once your blood pressure is stable, you’ll need surgery to correct toxic megacolon. In some cases, toxic megacolon may produce a tear or perforation in the colon. This tear must be repaired to prevent bacteria from the colon from entering the body.

Even if there’s no perforation, the tissue of the colon may be weakened or damaged and need removal. Depending on the extent of the damage, you may need to undergo a colectomy. This procedure involves either a complete or partial removal of the colon.

You’ll take antibiotics during and after the surgery. Antibiotics will help prevent a serious infection known as sepsis. Sepsis causes a severe reaction in the body that is often life-threatening.

Total proctocolectomy with Ileostomy »

How can I prevent toxic megacolon?

Toxic megacolon is a complication of IBDs or infections. If you have one of these conditions, you should follow your doctor’s advice. This may include making lifestyle changes and taking certain medications. Following your doctor’s advice will help control the symptoms of IBD, prevent infections, and reduce the likelihood that you’ll develop toxic megacolon.

What is the long-term outlook?

If you develop toxic megacolon and promptly seek treatment at a hospital, your long-term outlook will be good. Seeking emergency medical treatment for this condition will help prevent complications, including:

If complications of toxic megacolon occur, your doctor may have to take serious measures. Complete removal of the colon may require you to have an ileostomy or ileoanal pouch-anal anastomosis (IPAA) put in place. These devices will remove feces from your body after your colon is removed.

Content licensed from:

Written by: Darla Burke
Medically reviewed on: Jun 01, 2017: University of Illinois-Chicago, College of Medicine

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
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