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Crohn’s disease is a chronic condition that causes inflammation in your digestive tract, primarily in your small and large intestines.

Although doctors have identified several potential contributing factors to the development of Crohn’s disease, there’s no evidence that Crohn’s disease is contagious.

Keep reading to find out more about research into whether Crohn’s disease is contagious as well as potential causes of the condition and ways to help prevent it.

There’s no evidence that Crohn’s disease is contagious in the same way that a condition like a cold, the flu, or a transmissible disease is.

The next sections will explore several scenarios to give some more detail as to why you don’t need to worry that you might “catch” Crohn’s disease.

Physical contact

You can’t get Crohn’s disease from physical contact with another person. This includes contact like hugging, shaking hands, or even sharing food or drink.

There are contagious conditions that can cause temporary stomach upset, such as a norovirus infection. This very contagious virus causes diarrhea and vomiting. But this condition is temporary and doesn’t reflect the autoimmune dysfunction and chronic nature of Crohn’s disease.

Sexual transmission

Crohn’s disease is not sexually transmitted. Because sex organs are so close to the rectum or some engage in anal intercourse, people may wonder if the disease can be transmitted when the stool from a person with Crohn’s disease comes in contact with another person. Research does not support this idea.

Some conditions with similar symptoms to Crohn’s can be transmitted sexually. One example is sexually transmitted infectious (STI) colitis, which has many similarities to Crohn’s disease and other inflammatory bowel diseases. But it’s a much different condition with distinct causes, according to a small 2015 study.

Conditions such as syphilis and chlamydia can cause STI colitis. These causes are sexually transmitted. However, there is no link between STIs and Crohn’s disease.


Research does suggest a strong genetic component to Crohn’s disease. If you have a close family member, like a parent or sibling, with Crohn’s, you are more likely to get the condition due to shared genes, according to the National Institute of Diabetes and Digestive and Kidney Diseases

Crohn’s disease also has varying levels of severity among people that may have some link to genetics. Some people experience frequent flare-ups, while others do not, and some with Crohn’s disease respond well to medications while others do not.

Researchers have attempted to identify a link between a person’s severity of symptoms and their genes. Although researchers in a 2017 study found four genes that may have some link to Crohn’s disease, none of them appear to be linked to how likely you are to get it or how severe your symptoms are.

MAP theory

A 2010 case study reported that seven people in the same high school class who weren’t related were diagnosed with Crohn’s disease, leading researchers to identify some common environmental contributors that may have led this group of people to develop Crohn’s disease.

The researchers ultimately concluded that these individuals may have drunk or swam in contaminated water that contained a pathogen that triggered Crohn’s disease. According to a 2020 report, one such pathogen is a subspecies of Mycobacterium avium called paratuberculosis (MAP).

This pathogen causes a condition called Johne’s disease in cows, sheep, and other animals that is very similar to Crohn’s disease. According to a 2015 research review, researchers haven’t found a direct link between MAP infections and Crohn’s disease, especially since many people with MAP in their bodies have not developed Crohn’s.

However, even if MAP does cause Crohn’s disease, these bacteria aren’t thought to be contagious from person to person, according to the 2020 report above. Instead, it’s usually transmitted from contaminated material (like drinking water or food) to humans.

Crohn’s disease is a form of inflammatory bowel disease (IBD). For reference, another common IBD form is ulcerative colitis.

These conditions cause inflammation that can damage your intestines. Crohn’s disease causes damage in both your small and large intestine, while ulcerative colitis usually causes damage primarily in your large intestine.

These conditions are different from irritable bowel syndrome (IBS). This causes many symptoms similar to Crohn’s disease, including:

  • gas
  • bloating
  • stomach discomfort

But IBS doesn’t usually cause permanent damage to your intestines like Crohn’s or ulcerative colitis can.

Doctors haven’t pinpointed exactly one cause of Crohn’s disease. Researchers believe that Crohn’s disease results from a combination of genetic, environmental, and intestinal factors. None of these factors are thought to have a contagious origin.

But these factors together can then trigger your body’s immune system to “attack” your intestines and cause inflammation. This is why Crohn’s is considered an autoimmune disorder — the immune system attacks your intestines when it’s supposed to protect them.

Some risk factors may increase your chances of getting Crohn’s disease, including:

Medications and diet are considered a much smaller risk factor for Crohn’s disease in comparison to smoking.

The National Institute of Diabetes and Digestive and Kidney Diseases also notes that there are many things that don’t cause Crohn’s disease that may sometimes be incorrectly attributed to the condition, including stress or eating certain foods.

Based on what researchers know about Crohn’s disease, the best way to prevent it is to not smoke.

Smoking is the most known modifiable risk factor for Crohn’s disease, according to the National Institute of Diabetes and Digestive and Kidney Diseases. If you currently smoke, seeking resources like the quitline (1-800-QUIT-NOW) can help you identify ways to quit.

Other ways to help prevent Crohn’s disease or manage symptoms include:

There’s no evidence that any contagious diseases or pathogens cause Crohn’s disease, or that Crohn’s disease itself is contagious. You can’t catch it from another person or an animal.

Crohn’s disease has a complex set of causes that can trigger its development. If you have a close family relative with Crohn’s disease, talk with a doctor, a gastrointestinal (GI) specialist, or a genetic counselor about your risk factors.