Crohn’s disease is not typically life threatening, but it can increase the risk of severe complications, such as colon cancer and toxic megacolon. Treatment can help reduce these risks.

Crohn’s disease is a long-term condition and a type of inflammatory bowel disease (IBD).

It most commonly affects the ileum, which is the end section of the small intestine and the first section of the large intestine, or colon. However, it can affect any part of the gastrointestinal tract, from the mouth to the anus.

Depending on the location and extent of the disease, a person with Crohn’s may develop serious complications.

In this article, we identify some life threatening complications of Crohn’s disease and describe associated symptoms.

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According to the Crohn’s & Colitis Foundation, a person with Crohn’s is unlikely to die from the disease, but it can increase the risk of life threatening complications, such as severe infections and colorectal cancer.

Prompt treatment can increase the likelihood of a good recovery. A person can also take preventive measures to reduce their risk of these complications.

Below are some severe complications of Crohn’s disease:

Colorectal cancer

People with IBD have an increased risk of developing dysplasia. This occurs when abnormal cells form in the lining of the colon or rectum. Over time, these cells can become cancerous.

When Crohn’s disease affects the colon, a person may have an increased risk of colorectal cancer, compared with the larger population. The risk is higher for people who have had Crohn’s for 8–10 years or more.

A person can help a doctor detect dysplasia early and possibly prevent colorectal cancer by:

  • having a routine colonoscopy every 1–2 years
  • seeing a gastroenterologist every year
  • notifying a doctor of any new symptoms or concerns
  • following the treatment plan for Crohn’s disease
  • telling the doctor if a family member develops colorectal cancer
  • exercising regularly and eating a varied and nutritious diet

Despite the increased risk, most people with Crohn’s disease never develop colorectal cancer.

Nonetheless, it is best to be familiar with the symptoms and speak with a doctor if they occur.

According to the American Cancer Society, a person who receives a diagnosis of colorectal cancer in the early stage, before it has spread, has a 91% chance of living at least another 5 years compared with someone who does not have colorectal cancer. This rate falls to 13% if cancer has already spread to other parts of the body.

Symptoms to look out for

Symptoms to look out for include:

  • diarrhea or constipation lasting more than a few days
  • a constant feeling of needing to make a bowel movement
  • bleeding from the rectum
  • stools that are dark or contain fresh blood
  • abdominal pain or cramping
  • weakness and fatigue
  • unintended weight loss


Inflammation from Crohn’s disease can spread through the intestinal wall, creating an abscess.

As the abscess grows, it forms a small hole in the wall, and this hole can develop into a fistula. A fistula is an abnormal passageway that connects one organ to another. Most start in the bowel. They may connect to other parts of the bowel or other internal organs.

Sometimes, a fistula forms a tunnel from the intestine to the outer surface of the skin. Doctors call this an enterocutaneous fistula (ECF). Most people with an ECF experience at least one complication, such as malnutrition or sepsis. Without treatment, both conditions can be life threatening.

The mortality rate for an ECF ranges from 6–33%, depending on how soon a person receives treatment, among other factors.

Symptoms to look out for

The symptoms of a fistula will depend on the location, but some common symptoms include:

  • frequent urinary tract infections
  • nausea and vomiting
  • diarrhea
  • abdominal pain
  • vaginal symptoms, such as leaking urine from the vagina, or leaking gas or feces into the vagina

Without treatment, sepsis may develop. Symptoms of sepsis include:

  • signs of infection, including fever, fatigue, and pain
  • confusion
  • fatigue
  • severe pain or discomfort

Treatment options for fistulas include antibiotics and surgery. A doctor may also use a catheter to drain a fistula or a collagen matrix to plug the hole.

Intestinal obstruction and strictures

A stricture is a narrowing of the bowel passage due to a buildup of scar tissue. It can sometimes lead to an intestinal obstruction, with a risk of a tear and perforation in the colon.

A perforated colon can be life threatening, and a person may need surgery.

Symptoms to look out for

Symptoms of an intestinal stricture include:

  • severe abdominal pain and cramping
  • nausea and vomiting
  • constipation
  • a bloated and distended abdomen

Perforated colon

Chronic inflammation, abscesses, fistulas, and strictures can weaken points in the intestinal wall.

Over time, the wall can tear, or perforate, allowing bacteria and other infectious substances to leak from the intestine into the abdomen. The medical term for this is peritonitis, and it can lead to sepsis.

Symptoms to look out for

A perforated colon is a medical emergency. A person needs surgery to repair the hole in the intestine.

Symptoms of a perforated colon include:

  • severe abdominal pain
  • changes in bowel function
  • nausea
  • vomiting
  • fever

The outlook will depend on various factors, including the person’s age, other health factors, and how quickly they receive treatment. It can be life threatening.

Toxic megacolon

Toxic megacolon is a rare but life threatening complication of Crohn’s disease. It occurs when inflammation causes the colon to expand so much that it cannot contract.

The result is a buildup of gas that can cause the colon to burst, leaking harmful bacteria and toxins into the bloodstream. It can cause internal bleeding and shock or sepsis.

Symptoms to look out for

Symptoms of toxic megacolon include:

  • swelling and pain in the abdomen
  • frequent or bloody diarrhea
  • dehydration
  • a rapid heart rate
  • fever

The outlook will depend on the person’s age, how soon they have surgery, and other factors. Early surgery can significantly increase the chance of surviving after toxic megacolon.

Living with a chronic illness can severely affect a person’s mental health. Depression is a common complication of Crohn’s disease.

Anyone experiencing symptoms of a persistent low mood, sleep problems, and other signs of depression may benefit from seeking medical help.

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The 988 Suicide and Crisis Lifeline is available 24 hours a day at 988. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 988.

Find more links and local resources.

Was this helpful?

Here are some questions people often ask about life expectancy with Crohn’s disease.

Does Crohn’s affect life expectancy?

Crohn’s disease is not fatal, but it can have a severe impact on a person’s quality of life. It can also lead to various complications, some of which can be life threatening. Following a treatment plan and having regular medical checks can help prevent complications.

What is the average age that people receive a diagnosis of Crohn’s?

Crohn’s is most likely to appear between the ages of 15 and 30 years or 40 and 60 years.

Is Crohn’s a disability?

A person may qualify for disability benefits with Crohn’s, but this depends on how severely it affects their ability to carry out daily tasks. The person will need to undergo an evaluation of their symptoms, the effects of any treatment, and so on.

Crohn’s disease is not life threatening, but it can lead to life threatening complications. Most people with Crohn’s disease have a low risk of developing severe complications, as long as they follow their treatment plan.

Spotting any symptoms early and receiving prompt treatment can increase the likelihood of recovery from Crohn’s complications.

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