The complications of megacolon are massive bleeding, bowel perforation (rupture), sepsis (whole body infection), and even life threatening shock.
If toxic megacolon is left untreated it becomes fatal and requires emergency immediate medical treatment.
Toxic megacolon is the severe type of megacolon and can lead to complications which include:
Bowel Perforation: Extreme dilation stretches the bowel wall, creating tears or holes that allow stool and bacteria to leak into the abdominal cavity.
Sepsis and Shock: Leaking toxins and bacteria cause systemic infections (sepsis), leading to a drastic drop in blood pressure and organ failure (septic or hypovolemic shock).
Massive Gastrointestinal Hemorrhage: Severe inflammation and ulcers can lead to heavy blood loss into the stool.
Abdominal Compartment Syndrome: The heavily distended bowel compresses other organs and blood vessels in the abdomen.
Chronic Non Toxic Megacolon is less severe and often occurs as a result of long term conditions such as Hirschsprung's disease or chronic severe constipation like with Chagas disease and while it's not immediately toxic, it does carry some ongoing severe risks, which includes:
Stercoral Ulcers: Chronic pressure and hard stool (fecaloma) can erode the colon lining, creating painful open sores.
Spontaneous Perforation: Although rare (about a 3% risk), the bowel can suddenly tear from extreme overstretching or at the site of a stercoral ulcer.
Respiratory Compromise: A severely distended colon can displace the diaphragm, compressing the lungs and restricting breathing.
Volvulus: The heavy, elongated colon can twist on itself, causing a bowel obstruction that cuts off its own blood supply.
The causes of megacolon are congenital conditions like Hirschsprung disease, neurological disorders like Parkinson's disease, severe infections like C. diff and inflammatory bowel disease.
Megacolon is the abnormal widening of your large intestine and the causes of the megacolon will vary by the type of megacolon like acute, toxic or chronic megacolon.
Common causes of acute nontoxic megacolon also known as Ogilvie syndrome include:
Post Surgery or Trauma where it often occurs in people who are hospitalized and are recovering from major surgeries or severe trauma.
And critical illnesses like kidney disease, systemic infections or severe heart disease.
Common causes of chronic megacolon include:
Congenital (Hirschsprung Disease): The most common cause in children.
It is caused by the absence of nerve cells (aganglionosis) in the muscle walls of the colon, which prevents normal muscle contractions.
Neurological Diseases: Conditions that damage the nerves controlling the bowel, such as Parkinson's disease, multiple sclerosis, diabetic neuropathy, or spinal cord injuries.
Chagas Disease: Caused by the parasite Trypanosoma cruzi, this disease destroys the enteric nervous system and is one of the leading causes of chronic megacolon in Latin America.
Metabolic and Systemic Disorders: Hypothyroidism, electrolyte imbalances (e.g., severe hypokalemia), and connective tissue disorders like scleroderma.
Medication-induced: Long-term use of certain medications, such as some atypical antipsychotics and anticholinergic drugs, can significantly impair bowel motility.
The common causes of toxic megacolon which is a life threatening, acute condition where your colon widens rapidly due to severe inflammation include:
Inflammatory Bowel Disease (IBD): Ulcerative colitis and Crohn's disease.
Severe Colonic Infections: Bacterial infections such as Clostridioides difficile (C. diff), Salmonella, or Shigella.
Viral Infections: Cytomegalovirus (CMV) colitis, which is a leading cause in immunocompromised individuals or those with HIV/AIDS.
Ischemia: Insufficient blood flow to the colon.
Certain Medications: Antidiarrheal drugs (like loperamide) or certain narcotics can slow colonic motility and exacerbate or trigger the condition in already unwell patients.
The most common cause of megacolon depends on the type: Inflammatory Bowel Disease (IBD), particularly ulcerative colitis, is the most common cause of acute toxic megacolon.
Chagas disease (an infection by Trypanosoma cruzi) is the leading cause of acquired chronic megacolon worldwide.
Hirschsprung disease is the most common cause in infants.
The symptoms of a megacolon are abdominal discomfort, bloating and long term severe constipation.
The megacolon symptoms will also depend on the type including chronic megacolon and toxic megacolon.
Chronic megacolon symptoms include long standing, severe constipation, abdominal swelling, distension and tympany, which is a drum like sound upon tapping.
Other symptoms of chronic megacolon are nausea and vomiting, abdominal pain and gas discomfort, palpable and hard fecal masses.
Chronic megacolon is often acquired over years or present congenitally like in Hirschsprung disease in infants.
Toxic megacolon symptoms include severe abdominal pain, swelling and tenderness, frequent diarrhea which can be bloody, high fever that is often above 101.5 F and tachycardia, which is a rapid heart rate, that is often over 120 beats per minute.
Other toxic megacolon symptoms include signs of systemic toxicity, like confusion, altered mental status and dehydration as well as low blood pressure also known as hypotension, or shock (clammy skin, rapid shallow breathing.
Toxic megacolon is an acute and severe widening of your large intestine that is often triggered by inflammatory bowel disease or IBD or even severe infections such as C. diff.
Toxic megacolon requires immediate emergency medical attention.
If you or someone else experiences the symptoms of toxic megacolon you should get to the hospital as soon as possible or call 911 or an ambulance.
With megacolon you may also have altered bowel habits.
While diarrhea is common in the conditions that lead to toxic megacolon, people with megacolon may experience a sudden decrease in bowel movements as the colon loses its ability to contract effectively.