What is Toxic Megacolon?
Toxic megacolon is a seldom seen, yet potentially fatal issue tied to inflammation, or swelling of the colon. It’s identified as a swelling of the colon that’s not caused by a blockage. This colon swelling can either be throughout the entire colon or just affect a section of it and usually linked with general ill-health.1,2 The most common connection is with inflammatory bowel disease, particularly a type known as ulcerative colitis. However, any circumstance causing the colon to become inflamed may potentially lead to toxic megacolon.3
What Causes Toxic Megacolon?
Toxic megacolon is a serious condition that can occur as a result of diseases that cause infection in the large intestine. Here’s a list of some common causes:
Inflammatory Causes:
– Ulcerative colitis: which is a disease causing long-term inflammation and sores in the innermost layer of your colon and rectum.
– Crohn’s disease: which is a type of disease that causes inflammation of your digestive tract.
Infectious Causes:
– Clostridium difficile: it’s a bacteria that can infect the bowel and cause diarrhea.
– Salmonella, Shigella, & Campylobacter colitis: these are types of bacteria that are usually transmitted through contaminated food or water, which can lead to inflammation of your colon.
– Certain strains of Escherichia coli (E. coli): some types can cause severe bowel disease.
– Cytomegalovirus: it’s a common virus that can infect people of all ages, but it usually causes disease in people with weakened immune systems, like those with HIV and AIDS.
– Entamoeba: it’s a group of single-celled parasites that can cause diseases in humans when swallowed, such as through contaminated food or water.
Note that Cytomegalovirus is the main cause of toxic megacolon in people with HIV and AIDS, especially those with disseminated cytomegalovirus, which means the virus has spread throughout their bodies. On the other hand, Entamoeba is the least common cause.
Certain factors can trigger toxic megacolon, like:
– Hypokalemia: a condition in which the potassium level in your blood is lower than normal.
– Medications including those that slow down gut movements (antimotility agents), painkillers (opiates), muscle relaxants (anticholinergics), and antidepressants.
– Barium enema: a type of X-ray of the large intestine that involves a liquid that contains the element barium.
– Colonoscopy & bowel preparations: procedures performed to examine the inside of the colon and rectum.
Risk Factors and Frequency for Toxic Megacolon
Toxic megacolon is a medical condition that can happen to anyone, regardless of age or gender. However, those with inflammatory bowel disease, particularly in the early stages, are at a greater risk. It often affects those with Crohn’s disease before the colon suffers severe fibrotic (scarring) damage. Once severe scarring occurs, the colon isn’t able to expand.
Research on the condition in people with inflammatory bowel disease has given varied results. Some studies suggest that it’s more common in patients with ulcerative colitis than in those with Crohn’s disease, while other studies suggest the opposite.
Moreover, toxic megacolon may also occur as a result of a Clostridium difficile (C. difficile) infection. This infection can either have no symptoms or it can lead to severe disease including toxic megacolon. In recent years, cases of toxic megacolon connected to C. difficile colitis have been on the rise. Before 1990, the percentage of these cases rose from a mere 0.4% to 3%, and the number further grew to 4.3% after 1990.
Lastly, about 20% of hospitalized patients can have a C. difficile infection without showing symptoms, while the infection presents with symptoms in 1% of hospitalized patients.
Signs and Symptoms of Toxic Megacolon
Understanding a patient’s medical history is crucial for diagnosing health conditions. For instance, knowing if a patient has HIV/AIDS, their current medications, and any known exposures can guide doctors towards an accurate diagnosis. If a patient takes certain medicines like steroids, it could hide some symptoms of toxic megacolon, a severe bowel condition. Also, some drugs can worsen this condition, such as anticholinergics or opioids. If a patient comes with diarrhea and abdominal pain or bloating, doctors should consider toxic megacolon as a possible cause.
Patients with toxic megacolon often appear severely ill. They usually have symptoms like stomach pain and bloating, nausea, vomiting, diarrhea (sometimes with blood), and changes in awareness or behavior. During a physical exam, the doctor typically finds abdominal discomfort and reduced intestinal sounds. A study that looked at patients suffering from C. difficile infection and toxic megacolon found that the most common complaints were diarrhea, tiredness, and stomach pain or bloating.
- Stomach pain and bloating
- Nausea
- Vomiting
- Diarrhea (sometimes with blood)
- Changes in awareness or behavior
- Reduced intestinal sounds
Patients with toxic megacolon often have other health issues too. These can include imbalances in bodily fluids and electrolytes, low blood pressure, anemia, weight loss, straightforward diabetes, and kidney failure.
Patients with symptoms of peritonitis, including fever, abdominal pain, tenderness, mental status changes, and low blood pressure, may have a perforated bowel. If a patient is on steroids, these symptoms may not be apparent because steroids can hide some symptoms. However, if a patient on steroids still has fever after two or three days of treatment, doctors should consider the possibility of a perforated bowel.
Testing for Toxic Megacolon
If your doctor suspects you may have a condition called toxic megacolon, they will look at a variety of symptoms and use multiple tests to diagnose the condition. Key signs include symptoms like a fever or should a significant enlargement (6 cm or more) of the colon on x-ray images. In general, doctors look for at least three of the following signs:
* Fever higher than 38 degrees C
* Heart rate faster than 120 beats per minute
* High white blood cell count (neutrophilic leukocytosis) over 10500/micro/L
* Anemia (low red blood cell count)
As well as one of these:
* Dehydration
* Altered awareness or responsiveness
* Imbalance of body salts or chemicals (electrolytes)
* Low blood pressure (hypotension)
Your doctor may also look for signs like high body temperature or increased heart rate. Blood tests can show if you have anemia, which means a lower than normal amount of red blood cells, or a high white blood cell count, which could indicate infection or inflammation. Other tests might show increased levels of inflammation markers, such as erythrocyte sedimentation rate and C-reactive protein. If you have severe diarrhea and low levels of potassium and albumin, (a type of protein) in your blood, this could mean a worse outcome.
Your doctor might use an x-ray to help diagnose you, but they are also increasingly using computed tomography (CT) scans. These scans are used especially when the doctor needs to know more about the severity of your condition or if there might be complications from toxic megacolon like an abscess (a pocket of pus), a potential hole in the colon (perforation), or an infection in a vein that carries blood away from the intestines (pylephlebitis).
CT scans can show signs of toxic megacolon, such as a thickened wall of the colon and signs of inflammation near the colon. Another possible sign on a CT scan is the “accordion sign,” which is where differing levels of tissue density from inflammation make the colon look like an accordion.
An abdominal ultrasound might be used too, but these scans often don’t give specific enough findings to make a diagnosis.
Colonoscopies, where a doctor inserts a thin tube with a camera at the end into the colon, is not usually needed for diagnosing toxic megacolon. It’s actually not recommended due to the high risk of causing a hole, or perforation, in the colon.
Treatment Options for Toxic Megacolon
The treatment focuses on medically supporting the patient and providing proper care to avoid any rupture of the colon. It’s equally important to manage the root cause, correct any imbalances in the body’s electrolytes (like low potassium), manage symptoms, and prevent further complications.
Medical Management
At first, patients are provided with medical therapy and supportive care, which proves to be successful for about half of the patients. Patients are usually admitted to the intensive care units to closely monitor their health condition in case it suddenly worsens. Doctors regularly conduct blood tests, abdominal x-rays, and check the levels of electrolytes. Once the patients show signs of improvement, these tests are performed less frequently. Medications that can aggravate the condition, like opioids and anticholinergics, are halted. Patients are started on IV fluids to ensure they remain well-hydrated.
If there’s a high risk of colon rupture, antibiotics are typically provided, especially if an infection is the cause. The most common antibiotics used are metronidazole or vancomycin. If a type of virus known as cytomegalovirus (CMV) is suspected as the cause, a medication called ganciclovir is administered.
For patients with a disease known as ulcerative colitis, steroids are given promptly. High doses have not proven to bring significant benefits. Researchers have also studied the use of cyclosporine and infliximab for patients with ulcerative colitis. However, these are generally not recommended for the treatment of toxic megacolon.
Moreover, patients are advised to take a break from their usual diet. Using a nasogastric tube for stomach decompression can be helpful, but it won’t relieve pressure in the colon. As the patient starts to recover, they can gradually return to a regular diet, which can help heal the gut.
Surgical Management
It’s beneficial to have a surgeon involved in the patient’s care from the very first day, in case a surgical procedure may become necessary. The current surgical treatment of choice involves removing most of the colon and creating an opening on one side of the body for waste to leave the body (ileostomy).
There are no strict guidelines for when surgery should be performed. If the patient’s colon has ruptured, is bleeding, or if the patient’s condition is deteriorating, surgical intervention becomes unavoidable. However, some studies suggest that timely surgery after diagnosing toxic megacolon may lead to better outcomes. Other studies suggest increased mortality in patients older than 65.
Therefore, it’s important for surgeons and other doctors to monitor the patient’s condition daily while working together closely. This is essential because a rupture in the colon leads to a worse prognosis, increasing the death rate by 3 to 5 times.
What else can Toxic Megacolon be?
When a doctor is trying to figure out a diagnosis, they often consider several possible conditions. In the case of certain gastrointestinal problems, they might think about the following conditions:
- Hirschsprung disease
- Acquired megacolon
- Colonic pseudo-obstruction (also known as Ogilvie syndrome)
- Diffuse gastrointestinal dysmotility
What to expect with Toxic Megacolon
In patients who have inflammatory bowel disease, the death rates can be between 0 to 2%. This seems to be largely due to early diagnosis and better treatments available these days. If the colon gets perforated, it tends to make the disease a lot worse, and can increase the risk of death by 3 to 5 times. However, some studies suggest that early surgery can greatly reduce the death rate from 22% to just 1.2%. Conversely, other research has found increased mortality rates, particularly in patients over the age of 65.
Possible Complications When Diagnosed with Toxic Megacolon
If toxic megacolon isn’t treated correctly, there’s a danger of the colon bursting, which is a serious condition. Other severe complications are bowel perforations, abdominal infections, abscesses, and abdominal compartment syndrome, which is a life-threatening condition where increased pressure in the abdomen damages the body’s organs. These severe issues require immediate surgical treatment.
Severe Complications:
- Colon burst or rupture
- Bowel perforations
- Abdominal infections (peritonitis)
- Abscesses
- Abdominal compartment syndrome (damaging pressure in the abdomen)
Preventing Toxic Megacolon
Toxic megacolon, though not a common condition, is something that people, especially those with inflammatory bowel disease, should be aware of. Inflammatory bowel disease can increase the risk of developing toxic megacolon, so it’s necessary to understand what triggers it and what the potential symptoms could be. Recognizing the symptoms early and getting prompt medical treatment greatly improves the chances of survival. In simple terms, toxic megacolon is a serious condition where the large intestine suddenly swells up. People should be aware of this to ensure they get early treatment, which can be life-saving.
