Toxic megacolon is a serious condition of the large intestine, or colon, that affects how well food moves through the digestive system. Digestive symptoms like bloating and nausea are common.
Almost half of all toxic megacolon cases are triggered by inflammatory bowel diseases (IBDs), like ulcerative colitis. Prompt medical treatment is vital to minimize the risk of complications.
If you have toxic megacolon, you may feel generally unwell. The most common symptom is severe, bloody diarrhea. You may develop anemia from the blood loss. If you’re anemic, you may feel tired or weak, be short of breath, or become dizzy with exercise.
Other symptoms of toxic megacolon may include:
- Bloated stomach that feels tender or painful
- Rigid abdomen due to abdominal guarding (when stomach muscles tense to block pain and protect the colon)
- Fever over 100.4 degrees Fahrenheit (38 degrees Celsius)
- Chills
- Nausea or vomiting
- Change in mental state, such as feeling confused, drowsy, or like something’s not right
As the condition worsens, more severe symptoms of toxic megacolon can include:
- Drop in blood pressure
- Raised heart rate
- Low potassium levels, leading to symptoms like muscle weakness, cramping, and a pounding or skipping heartbeat
- Dehydration, including symptoms like dark urine, headache, dizziness, or lightheadedness
Anything that causes inflammation in your colon could cause toxic megacolon. Inflammatory bowel diseases, like ulcerative colitis and Crohn’s disease, cause long-term changes to your colon that could trigger toxic megacolon.
Infections can sometimes lead to toxic megacolon. Bacterial and viral infections that can cause inflammation in the colon include:
- Clostridium difficile (C. diff)
- Salmonella
- Cytomegalovirus (CMV)
- Shigella
More research is needed to understand the connection between inflammation and toxic megacolon. Studies suggest that infections or health conditions cause inflammation in the inner layer of the colon. This deep inflammation further increases widespread colon inflammation and gas.
Typically, your gastrointestinal tract contracts rhythmically to move digested food forward. When your colon becomes inflamed and gaseous, it relaxes instead of contracting. Eventually, the colon becomes paralyzed. Because no active muscle is holding its shape, the colon widens and food is unable to move through your system. In severe cases, the colon can rupture.
Risk Factors
Certain health conditions, medications, and gastrointestinal procedures can increase your risk for toxic megacolon. These include, but may not be limited to:
- Inflammatory bowel disease, especially in early stages
- Antimotility agents (medications that slow intestinal contractions, often used to treat diarrhea)
- Opiates (pain-relieving drugs)
- Antidepressants
- Colonoscopy (internal exam of your lower digestive tract)
- Barium enema (exam of the colon and rectum that requires access to your lower digestive tract)
- Bowel preparations that clean out your colon before a procedure
Your healthcare provider will ask questions about your medical history to determine if you have any infections or health conditions that may cause toxic megacolon. After a physical examination, they may perform the following diagnostic tests:
- Computed tomography (CT) scan: An imaging test used to visualize the thickness of the colon’s wall and other signs of inflammation
- Abdominal X-ray: An imaging test to determine the width of the colon
- Blood tests: Laboratory testing to determine if your red blood cell count is low, potassium is low, or white blood cell levels are high
After you receive a diagnosis, your healthcare team will create a treatment plan to support your individualized needs.
If left untreated, toxic megacolon is fatal. The goal of treatment is to reduce inflammation and improve movement in the colon. Another key goal is to minimize the risk of perforation (a hole in the wall of the colon), a complication of toxic megacolon.
Once you’re diagnosed with megacolon, you need to rest your bowel to give it time to heal. This may involve fasting for a period, following a clear liquid diet, or receiving nutrients through a nasogastric tube (a thin tube inserted through your nose into your stomach to deliver food, fluids, and medicine directly to your stomach). As your condition improves, you can slowly start to eat and drink again.
Medications
Medication is typically the first line of treatment for toxic megacolon. About half of all toxic megacolon cases are resolved with medication and other nonsurgical medical care. Medical treatment may include:
- Antibiotics: Antibiotic drugs, such as Firvanq (vancomycin), are used to treat current infections causing bowel inflammation as well as any future infections resulting from bowel perforation.
- Steroids: Corticosteroids, such as Medrol (methylprednisolone), are used to manage inflammation in the colon, especially in people with inflammatory bowel disease.
- Fluids: Administered intravenously (through an IV), fluids help treat or prevent dehydration.
Surgery
Your healthcare team may recommend surgery if your colon perforates, a part of it dies, or you develop another complication. During surgery, your team will remove a section of your colon. In some cases, they may remove the entire colon.
If a portion of your colon is removed, you may need an ileostomy. An ileostomy is a surgical opening in your stomach. It allows fecal matter to exit your body after a portion of your colon is removed. The fecal matter is held discreetly in a pouch until it’s emptied. This pouch is worn at all times.
You may be able to lower your risk of developing toxic megacolon by preventing infections that could cause it. A few ways to reduce your infection risk include:
- Wash your hands after using the bathroom, before eating, and after touching any animals.
- Practice food safety, especially when preparing raw meat, poultry, and seafood.
- Avoid eating around animals or kissing pets.
- Bring pets to the veterinarian for regular vaccines and pest control treatments.
- Don’t swallow water when swimming in pools, lakes, or other water areas.
- Be mindful of which foods and drinks are safe to have when traveling internationally.
You may also be able to prevent toxic megacolon by seeking prompt professional care for your inflammatory bowel disease. If you have IBD, talk to your healthcare provider about what you can do to avoid this complication.
Perforation of the bowel is a rare but major complication of toxic megacolon. A perforation is a hole in your colon and requires immediate emergency medical care. When you have a perforation, all the contents of your bowel leak out into your abdomen. The acidic contents from your stomach, half-digested food, or fecal matter can cause harm to the surrounding tissue.
Other complications of toxic megacolon include:
- Anemia: Low red blood cell count caused by the loss of blood through bloody bowel movements
- Electrolyte imbalances: Low levels of potassium and albumin (a protein that helps regulate fluid levels in the body)
- Weight loss: Unwanted weight loss due to persistent diarrhea and the inability to properly digest food
If you think you may have toxic megacolon, seek emergency care immediately to lower the risk of complications. Prompt medical treatment may reduce your risk of perforation.
Toxic megacolon is a rare but serious complication of inflammatory bowel disease or certain infections. Inflammation from these conditions can paralyze the colon, causing symptoms like bloody diarrhea, vomiting, and fever. Your healthcare provider may request imaging tests like a CT scan or an abdominal X-ray to diagnose you with toxic megacolon.
Treatment for toxic megacolon may include a clear liquid diet, steroids, and antibiotics. Some people may require surgery to remove a portion or the entire colon. You can take steps to prevent infection and reduce your risk of toxic megacolon.
