Risk Factors for Developing Crohn’s Disease

thuynhUC Learn

Crohn’s disease, a chronic inflammatory illness that affects the gastrointestinal tract, can cause symptoms that commonly include pain and severe diarrhea.

According to the Crohn’s and Colitis Foundation of America, as many as 700,000 Americans have this disease.1

It’s not completely understood what causes this disease. Experts think that your body’s immune response mistakenly overreacts to the bacteria found in your intestine. This response is thought to be triggered by exposure to something in your environment. Differences in our genetic makeup cause one person who’s exposed to the same trigger to develop Crohn’s disease, while another person stays healthy.

Experts have identified the following as risk factors:

  • Genetic factors: Crohn’s disease can run in families, so if a close family member has it, chances are greater than average that you may develop it as well, too. Up to 20 percent of people with this disease also have a “first degree relative (parents, full siblings, or child) who also has Crohn’s.2 Some studies have also shown that a number of genes can increase the risk for developing Crohn’s disease.3 However, genetic testing for Crohn’s is still in its early stages of testing.
  • Ethnicity: If you are Caucasian or have an Eastern European Jewish background, you have a greater chance of developing Crohn’s. People from any race can have it, however.
  • Smoking: Cigarette smoking increases your risk of developing the disease. It’s the most important risk factor that’s under your control. If you already have Crohn’s disease, smoking can make it worse. Smokers don’t respond as well to some treatments and are more likely to have the disease recur after surgery.4
  • Age: You can develop Crohn’s at any age, but it’s most common in younger people. Most people are diagnosed before age 30, with most patients in the 15-35 age range. About 10 percent5 of people are diagnosed when they’re younger than 18.
  • Where you live: People who live in urban areas or industrialized countries are more likely to have Crohn’s. This may be because people in these countries have a diet that’s higher in fat and refined sugars and other processed foods.
  • Certain medicines: It’s thought that non-steroidal anti-inflammatory medications (NSAIDs) could possibly cause this disease to develop, but to date, there is no conclusive evidence. NSAIDs include ibuprofen and naproxen. These medicines can also cause flares of symptoms in people who already have Crohn’s.

Falsely identified risk factors

There’s some confusion over several things that are commonly thought to be risk factors, but they actually aren’t. These include:

  • Stress: Some people think stress causes Crohn’s disease, but this hasn’t been proven.
  • Dairy products, fruits, and vegetables: Some Crohn’s disease patients may mistakenly limit their consumption of dairy products and fruits and vegetables. Except in very limited circumstances, this doesn’t help avoid flare-ups and can instead deprive you of vital nutrients.

Discuss any risk factors you may have with your doctor, especially if you’ve already had what you think might be symptoms of Crohn’s disease. If you smoke, get help and advice to quit, since this risk factor is under your control.


1 Available at http://www.ccfa.org/what-are-crohns-and-colitis/what-is-crohns-disease/. [Accessed September 21, 2015].
2 Russell RK, Satsangi J. Does IBD run in families? Inflamm Bowel Dis. 2008;14(S2):S20-S21.
3 Noomen CG, Hommes DW, Fidder HH. Update on genetics in inflammatory disease. Best Pract Res Clin Gastroenterol. 2009;23(2):233-243.
4 Duffy LC, Zielezny MA, Marshall JR (1990) Cigarette smoking and risk of clinical relapse in patients with Crohn’s disease. Am Rev Prev Med 6:161–166.
5 Cuffari C. Diagnostic Considerations in Pediatric Inflammatory Bowel Disease Management. Gastroenterology & Hepatology. 2009;5(11):775-783.