The large intestine is the lowermost 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 intestines 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 meant to express the seriousness of the condition.
Toxic megacolon is a rare, life-threatening widening of the large intestine that develops within a few days. It’s usually a complication of inflammatory bowel disease (such as Crohn’s disease).
The root causes of toxic megacolon are inflammatory bowel diseases (IBDs). Inflammatory bowel diseases cause swelling and irritation in parts of your digestive tract. These diseases can be painful and can cause permanent damage to your large and small intestines. Examples of IBDs are ulcerative colitis and Crohn’s disease.
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 a life-threatening condition. If your intestines rupture, bacteria that are normally present in your intestine release into your abdomen, which 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 may include:
- abdominal pain
- bloating of the abdomen (distention)
- abdominal tenderness
- rapid heart rate (tachycardia)
- bloody or profuse diarrhea
- painful bowel movements
Toxic megacolon is a life-threatening condition. If these symptoms develop, you should seek immediate medical attention.
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 any inflammatory bowel diseases. 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:
- abdominal X-rays
- CT scan of the abdomen
- blood tests such as a complete blood count (CBC) and blood electrolytes
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 occurs when an infection in the body causes your blood pressure to decrease rapidly. Shock is a life-threatening condition.
Once your blood pressure is stable, you will need surgery to correct toxic megacolon. In some instances, toxic megacolon may produce a tear or perforation in the colon. This tear must be repaired to prevent bacteria from the colon from entering into the body.
Even if there’s no perforation, the tissue of the colon may be weakened or damaged and may need to be removed. 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.
During and after the surgery, you will take antibiotics. These medications will help prevent a serious infection known as sepsis. Sepsis causes a severe reaction in the body that is often life-threatening.
Toxic megacolon is a complication of inflammatory bowel diseases. 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 and reduce the likelihood that you’ll develop toxic megacolon.
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:
- perforation (rupture) of the colon
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.