Share on Pinterest
10’000 Hours/Getty Images

Crohn’s disease is a type of inflammatory bowel disease (IBD). It primarily affects the ileum, or the end section of your small intestine. It’s also commonly found in the first section of your colon, or your large intestine.

The symptoms of Crohn’s can be troublesome, and sometimes interfere with day-to-day life. But Crohn’s is not usually fatal or life threatening — if it’s treated properly.

Untreated Crohn’s can lead to life threatening complications. Keep reading to learn about the potentially fatal complications of untreated Crohn’s disease, as well as the symptoms that tell you it’s time to contact a doctor or emergency department.

Untreated Crohn’s disease can be uncomfortable, and even painful. You may experience more frequent:

  • abdominal cramps
  • diarrhea
  • fatigue

But there are some complications of untreated Crohn’s that are severe and potentially life threatening. These complications should be taken seriously. Proper treatment is the only way to prevent these complications.

Colorectal cancer

A 2016 research review showed that individuals with IBD are at a higher risk of developing colorectal cancer, or cancer in the lining of the colon or rectum. The risk is even higher for people who’ve had Crohn’s disease for a decade or more.

Chronic inflammation from untreated Crohn’s can play a role in the development of early-stage abnormal cells (also known as dysplasia) that can become cancerous.


Chronic inflammation in your intestines can cause a series of health complications. One of the most serious complications is a fistula. This is a tunnel or atypical connection between your intestinal walls and other parts of your body, such as another organ or tissue.

When these tunnels form, fluid from your stomach or gastrointestinal (GI) tract can escape to other parts of your body, into other organs, or into your abdominal cavity. This can lead to a fatal infection called sepsis.

It can also cause malnutrition, which occurs when your body does not absorb the nutrients it needs in your GI tract. Over time, a lack of proper nutrition can be life threatening.

According to Crohn’s and Colitis UK, an estimated 1 in 4 people with Crohn’s will develop this complication.

Bowel obstruction

Chronic inflammation can also cause scar tissue throughout your GI tract. This can lead to narrowing, or strictures, in your intestine. This may make it difficult for stool to pass. Over time, this can also lead to a complete obstruction, which may cause a tear in your colon.

A bowel obstruction or intestinal blockage is the most common Crohn’s complication, but it doesn’t make it any less fatal. Emergency treatment is necessary to prevent a fatal infection, or sepsis.

Perforated colon

Crohn’s complications can all weaken points along your intestinal wall. These complications include:

  • chronic inflammation
  • strictures
  • fistulas

Over time, these weak points may tear, or perforate. This will allow bacteria and other substances from your intestines to spill out into your abdomen. This can lead to a type of infection called peritonitis.

If peritonitis is left untreated or not treated properly, it can lead to sepsis or blood poisoning. These are both life threatening conditions.

Toxic megacolon

This condition occurs when inflammation and gas in your intestines cause your bowels to expand so much they’re no longer able to contract.

If the pressure is not relieved properly, your colon can burst. This will allow bacteria and other substances to leak into your abdomen and bloodstream. If not treated immediately or properly, this can lead to:

  • internal bleeding
  • sepsis
  • shock

This life threatening complication of Crohn’s is rare. It’s actually more common in people with another type of IBD called ulcerative colitis.


People living with Crohn’s often face ongoing health concerns with improper nutrition, or malnutrition. That’s because inflamed intestines may not be able to absorb nutrients as well as healthy intestines.

Over time, this can lead to problematic — and even life threatening — nutrient deficiencies.

People with Crohn’s often experience side effects and symptoms of the disease like:

  • diarrhea
  • stomach cramps
  • fatigue

While some of the most general symptoms of these potentially fatal complications are similar to these everyday Crohn’s symptoms, there are a few symptoms that stand out as potentially problematic.

Make an appointment with a doctor if you experience these symptoms

Schedule an appointment with a doctor if you experience any of the following symptoms:

  • constantly feeling as if you need to have a bowel movement but not producing one
  • bleeding from rectum
  • stool that is dark or shows blood
  • constipation
  • nausea or vomiting

Seek emergency care if you experience these symptoms

Some Crohn’s disease complications require emergency treatment. If you experience any of these symptoms, seek help immediately:

  • leaking urine, gas, or feces from your vagina
  • high fever
  • confusion
  • severe abdominal pain
  • loud noises coming from your abdomen

The sooner you contact a healthcare professional, the sooner they will be able to find out the possible complication happening and begin treatment. This increases the likelihood of recovery.

Treatment can help ease the symptoms of Crohn’s. You might even enter periods of remission, where symptoms of this IBD are less common, even nonexistent.

Crohn’s disease is a type of inflammatory bowel disease. There is currently no cure, but treatment can help people with the condition to go about their lives with fewer periods of increased symptoms.

It’s important to know that untreated Crohn’s disease can be fatal. That’s because the chronic inflammation associated with this bowel condition can lead to many severe and fatal complications.

Most people with Crohn’s may never face one of these complications. But that outcome depends on proper and regular treatment.

For people living with this condition, prompt treatment is vital. The sooner you contact a healthcare professional, the sooner a treatment can begin. This can improve recovery chances and help you prevent further complications.