Toxic Dilation of the Colon - Toxic Megacolon

Toxic megacolon is a serious complication that can follow inflammation or infection of the large bowel, or colon. It causes marked enlargement of the colon.

What is going on in the body?

The colon is the part of the bowel that attaches to the rectum and anus. When the colon becomes inflamed or infected, it may enlarge. Toxic megacolon describes a dangerous enlargement of the colon. This may result in a life-threatening tear, or perforation, of the colon.

What are the causes and risks of the condition?

The two primary causes of this condition are infections and inflammation. Inflammation is usually due to a condition known as inflammatory bowel disease (IBD). IBD can cause inflammation in the lining of the colon for unknown reasons.

Medications used to control diarrhea may also raise the risk of this condition in some cases. Low blood levels of potassium may do the same.

What are the signs and symptoms of the condition?

Symptoms of toxic megacolon may include:

On physical exam, the person looks quite ill. If a tear in the colon has occurred, the person is likely to show signs of peritonitis. These signs may include a hard, rigid abdomen, and severe abdominal tenderness.

How is the condition diagnosed?

The person's medical history and a physical exam are important in making the diagnosis. Abdominal x-rays can help confirm the diagnosis by showing a severely enlarged colon.

What can be done to prevent the condition?

Early treatment of inflammatory bowel disease flare-ups may help prevent toxic megacolon. Medications to control diarrhea should be used with caution when the colon is inflamed or infected.

What are the long-term effects of the condition?

Toxic megacolon is life-threatening and may result in death. A person who develops a tear in the colon will require surgery. A colectomy, the removal of part or all of the colon, may be needed.

What are the risks to others?

Toxic megacolon is not contagious and poses no risks to others.

What are the treatments for the condition?

Once toxic megacolon is diagnosed, the person is asked not to eat or drink anything. Fluids and salt are given intravenously (IV), which means through a vein. If the person's blood count is low, blood transfusions may be given. Gastric suctioning, a procedure in which a thin tube is used to remove stomach contents, can help reduce abdominal bloating. Antibiotics are usually given to kill bacteria. IV steroids, which are medications that reduce inflammation, may also be given.

In some cases, food is given intravenously. Someone with a suspected or known tear of the colon will need surgery to remove part or all of the colon.

What are the side effects of the treatments?

Antibiotics can cause stomach upset and allergic reactions. Other side effects vary depending on the medication that is used. Surgery carries the risk of bleeding, infection, and allergic reactions to anesthesia.

What happens after treatment for the condition?

If the person recovers completely from toxic megacolon, no further treatment may be needed. Some people have no long-standing problems from this condition, especially if surgery is not needed. However, a person with inflammatory bowel disease will need lifelong treatment.

Those who had surgery for this condition need follow-up visits with the surgeon to ensure proper healing. Sometimes a second operation is needed in the future.

How is the condition monitored?

After recovery from toxic megacolon, the person will need no further monitoring if the cause was an infection. A person with inflammatory bowel disease will need lifelong monitoring. Any new or worsening symptoms should be reported to the healthcare provider.

Author:Minot Cleveland, MD
Date Written:
Editor:Coltrera, Francesca, BA
Edit Date:07/19/00
Reviewer:Adam Brochert, MD
Date Reviewed:08/09/01

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