Smoking may increase your risk of developing Crohn’s disease but can also make the disease worse. Quitting smoking can improve your outlook and reduce your risk of complications with Crohn’s.

Crohn’s disease is a common inflammatory bowel disease (IBD) that primarily affects your small intestine and a portion of the upper large intestine. Like other types of IBD, such as ulcerative colitis (UC), Crohn’s disease causes cycles of flare-ups (worsening symptoms) and remission (absence of symptoms).

For unknown reasons, Crohn’s disease cases are increasing in number in the United States and globally. There is no single known cause of IBD, including Crohn’s, though there are several suspected risk factors.

Here’s what the research suggests about smoking and its risks with Crohn’s disease.

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) identifies smoking cigarettes as a risk factor for developing Crohn’s disease.

Still, not all smokers will develop Crohn’s disease, and not everyone diagnosed with this type of IBD has a history of smoking.

The ways smoking may contribute to Crohn’s disease aren’t clear. However, experts think that smoking might:

Crohn’s disease most commonly develops in adults ages 20–29 years and those with a family history of IBD.

Smoking not only increases your risk of developing Crohn’s disease but may also cause you to experience more flare-ups. This means you may experience more frequent or worsening:

People with Crohn’s disease who smoke also have:

  • less response to Crohn’s treatments
  • higher rates of hospital visits
  • increased need for surgery

Vaping and Crohn’s disease

Vaping has increased as an alternative to cigarette smoking in recent years. Though such products don’t have the carbon monoxide and tar found in traditional cigarettes, e-cigarettes are still not a healthy option.

The effects of vaping on Crohn’s disease aren’t clear. More clinical studies are needed to determine what adverse effects e-cigarettes might pose to IBD.

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Quitting smoking can improve your overall health, and it may also help with Crohn’s disease. By quitting smoking, you may experience:

  • fewer flare-ups
  • reduced risk of complications, including strictures and cancer
  • less likelihood of needing surgery
  • decreased risk of surgery-related complications
  • reduced need for certain medications, such as steroids

If your Crohn’s disease affects your large intestine, you may be at an increased risk of developing colon cancer. Treatment can help reduce this risk.

Also, smoking cigarettes may increase your risk of colorectal cancer development and related death. Research also links continuing to smoke after some colorectal cancer treatments to cancer recurrence.

If you have Crohn’s disease or risk factors for developing IBD, consider the following common questions about the relationship between smoking and digestive conditions.

Can smoking cause inflammatory bowel disease?

It’s unclear whether there’s a direct cause-and-effect relationship between smoking and IBD. However, research does suggest that smoking may increase your risk of developing IBD, particularly Crohn’s disease and microscopic colitis.

Can smoking protect against ulcerative colitis?

Some research suggests that the rate of UC is higher in nonsmokers than in smokers. One such study in 2021 found that people with UC who smoked had lower levels of inflammation than people with Crohn’s disease who smoked.

However, the reasons for this are unclear. Also, another 2022 study found that while smokers with UC had fewer rates of hospitalization, they were at a higher risk of cancer and death.

Given the range of other adverse health effects associated with smoking, a doctor will recommend you try to quit.

How does smoking affect your intestines?

Though the exact causes aren’t clear, experts think smoking might alter bacteria in your intestines and increase the likelihood of leaky gut. This could, in turn, allow toxins to enter your bloodstream and cause an immune system reaction.

Support for quitting smoking

Quitting smoking isn’t easy, but the potential health benefits are well worth the effort. Working with a doctor can help you stay on track and give you access to support, such as medications.

Numerous online resources can help you begin your journey to quitting smoking:

You can also call Quitline at 800-QUIT-NOW.

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Smoking is linked to an increased risk of numerous health problems, and Crohn’s disease is among them. Smoking when you have Crohn’s disease may also worsen your symptoms, reduce periods of remission, and cause other complications.

If you have Crohn’s disease and currently smoke, consider working with a doctor on a plan to help you quit. By not smoking, you can potentially improve your outlook with Crohn’s disease and your overall health.