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 megacolonor 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).

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.

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

• abdominal pain
• bloating of the abdomen (distention)
• abdominal tenderness
• fever
• rapid heart rate (tachycardia)
• shock
• bloody or profuse diarrhea
• painful bowel movements

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

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.

What is the long-term outlook?