Is Crohn's Disease Genetic?

Crohn's disease is a form of inflammatory bowel disease (IBD) that causes inflammation in the lining of the digestive tract resulting in abdominal pain and cramps, bloody stools, persistent diarrhea, fatigue, and weight loss that can lead to malnutrition. The disease can affect any area of the digestive tract, from the mouth to the anus, but most commonly impacts the small intestine and the beginning of the large intestine.

The disease can affect any area of the digestive tract, from the mouth to the anus, but most commonly impacts the small intestine and the beginning of the large intestine.

More than 500,000 people in the United States have Crohn's disease.

The exact cause of Crohn's disease is unknown, but researchers believe a combination of factors like an autoimmune reaction, genetics, and lifestyle factors may play a role.

This article discusses the role genetics plays in Crohn's.

Risk Factors

To date, researchers are unsure exactly what causes Crohn's disease, but there are a number of risk factors that could contribute to it, including the following items.

Genes

Genetics is likely to play a role in Crohn's disease. Roughly 15% of people who live with Crohn's disease have an immediate family member who also has the disease.

Genetic factors affecting Crohn's disease include:

• If both parents have IBD, either Crohn's or ulcerative colitis, their child is more likely to develop IBD.
• People of Eastern European heritage, particularly Ashkenazi Jews, are at high risk, with risk increasing among African American populations.
• Variations in certain genes, namely NOD2, IRGM, IL23R, and ATG16L1, can interfere with the ability of cells in the intestines to properly respond to bacteria, causing the inflammation seen in Crohn's disease.

Environment

Environmental factors that cause Crohn's disease are still being studied, however, it is believed that there are certain factors related to the environment that may increase the risk of Crohn's disease.

For example, Crohn's disease is more common in developed countries than in underdeveloped nations. It is also more common in urbanized areas than rural areas.

This suggests issues related to sanitation and industrialization may play a role in the development of the disease.

Crohn's is also more common in northern rather than southern climates.

Immune system

Researchers believe one possible cause of Crohn's disease is an autoimmune reaction—when the immune system mistakenly attacks healthy cells. This is believed to be triggered by bacteria in the digestive tract. The resulting immune response can cause inflammation throughout the gastrointestinal tract, causing the symptoms seen in Crohn's disease.

Inheriting Crohn's vs. Having a Predisposition

It is not clear whether Crohn's disease is an inherited (genetic) condition as a number of factors are involved in the development of the disease.

What is known, however, is that if a family member has an autoimmune disorder—like Crohn's—other members of that family are at risk of developing the same disease or another kind of autoimmune disease. But this does not necessarily mean that if one family member has Crohn's disease, others will too.

Risk factors

If both parents have IBD (Crohn's or ulcerative colitis), the child is more likely to develop IBD.

Crohn's is most common in people of Eastern European heritage, including Jews of European heritage.

Reducing Your Risk

There is no way to prevent Crohn's disease, but the management of certain lifestyle factors may help lower risk, including the following:

• Quitting smoking: Smoking cigarettes doubles the risk of developing Crohn's disease. Stopping smoking will lower this risk.
• Eating healthy: A high-fat diet is believed to raise the risk of the disease. Eating a low-fat, healthy diet may help reduce risk.
• Exercising regularly: Exercising and reducing stress may also lower your risk.

Outlook

Although there is no cure for Crohn's disease, many people with the condition live healthy, rewarding lives.

There are a number of treatments available to help keep the disease in remission, which is the time when symptoms subside.

Making changes to your diet can also help reduce the severity of symptoms. People with Crohn's may find the following diet tips helpful:

• Avoiding carbonated beverages
• Avoiding popcorn, nuts, and high fiber foods
• Eating small meals more regularly
• Drinking more liquids

A Word From Verywell

Crohn's disease has no definitive cause. Autoimmune response, genetics, and lifestyle factors all play a role. Having an immediate family member with Crohn's increases the risk for the condition, but it is not an inherited disease. If you have any concerns about your health or are worried you might be at risk of developing Crohn's, you should speak with a healthcare provider.

Frequently Asked Questions

How is Crohn's disease diagnosed?

A healthcare provider will use a variety of tests to reach a diagnosis of Crohn's disease. These may include:

• Physical exam of the abdomen
• Blood tests
• Endoscopy
• Colonoscopy
• CT (computed tomography) scan

What are the symptoms of Crohn's disease?

Symptoms of Crohn's disease can vary. Common symptoms include:

• Diarrhea that persists
• Bleeding from the rectum
• Cramping and abdominal pain
• Urgent need to have a bowel movement
• Feeling like a bowel movement is incomplete
• Constipation

How do you cure Crohn's disease?

There is no cure for Crohn's disease, but treatment options are available to keep the disease in remission.

Possible treatments include medication, bowel rest (giving your digestive system a break from eating any food by mouth), and surgery.