Crohn’s Disease FAQ

What is the main cause of Crohn’s disease?

Crohn’s disease is an autoimmune disorder resulting in chronic inflammation of the intestines, which arises due to a weak immune system, genetic factors, environmental factors, and lifestyle factors.1 In the body, there are harmless bacteria in the gastrointestinal tract which help to break down food.1  A potential cause of Crohn’s can be when this bacteria is seen as a foreign substance in the body, which then triggers an immune response.1 As a result of this immune response, there is usually chronic inflammation and thickening of the intestinal wall, which is a sign of Crohn’s.

Genetic factors increase the risk of developing this disease. A study deduced that 2-14% of patients with Crohn’s have either a parent or close relative with the same disease.2 In fact, your chances of developing this disease are doubled if both parents have Crohn’s.1 If there is a family history of this disease, you should consult the GP, who will monitor your health and potential symptoms. Environmental factors that include air pollution can also provoke the onset of this disease. Air pollutants increase the rate of inflammation and can change the effect of the harmless bacteria in the gut.3 

There are also several lifestyle factors to account for when thinking about potential triggers of this illness. Smoking is a known risk factor for the development of this disease and can lead to more intestinal complications than for those patients who are non-smokers.3 A high-fat diet and a lack of vitamin D can also lead to an onset of Crohn’s.3 Mental health issues, in particular depression and anxiety, have been found in a study to increase the prevalence of the disease and increase the relapse rate.3 

Why is Crohn’s disease more common now?

The prevalence of this disease is rapidly increasing due to the worsening of environmental factors, notably air pollutants and air pollution.4 The rate is increasing linearly with the number of pollutants in the air. A mixture of both industrialization and a western lifestyle, including smoking and a high-fat diet, has increased the odds of developing the disease worldwide.4  

Why is it called Crohn’s disease?

It is named after the first doctor, Burrill B. Crohn, who described the disease in 1932, with the most common symptom being inflammation in the small intestine.5 Since 1932, research surrounding the causes and treatment plans has reached unprecedented heights, especially with the advancement of technology. 

Is Crohn’s disease serious?

The disease is chronic, which means that your symptoms are recurrent, with periods of flare-ups and remission (when you do not experience any symptoms).6 This can last anywhere between 3-6 months or longer. You must consult a doctor in order to help you manage your symptoms and pain on a day-to-day basis. 

Serious complications can arise if this disease is left untreated including:6

  • Fissures (tears in the anus), which can lead to bleeding during bowel movements 
  • Fistula, which is where due to inflammation, an abnormal channel builds in the anal area
  • Stricture, which occurs when the intestines start to narrow as a result of the high rate of inflammation.

An array of other conditions can occur if this disease is left untreated, so the above only outlines the most common complications. These complications need immediate medical attention.  so if you feel any abnormal symptoms to your normal ones, then a doctor or GP should be contacted. 

Can Crohn’s affect your mind?

When discussing the relationship between the mind and Crohn's disease, there are two aspects to consider - the physiological aspect of the brain and the mental health repercussions. In a study in 2017, it was deduced that Crohn’s can lead to cognitive impairment with symptoms ranging from concentration issues to cloudy thoughts.7 These symptoms do not occur for all those who suffer from the disease; however, if you notice any of these, then you should contact a GP or healthcare specialist. 

On the flip side, Crohn’s can affect your mind in a manner that can lead you to suffer from mental health disorders. As it is a long-term condition, it goes without saying that this can cause frustration, anger, and sadness, among other emotions. However, a cohort study in the UK in 2020 found that people who suffer from Crohn’s have a higher prevalence rate of developing both depression and anxiety.8 The study goes on to suggest that mental health interventions should be implemented,8 and this can include going to a support group or speaking to a therapist in order to formulate a plan to manage the fluctuations in emotions. Crohn’s can affect your mind through physiological damage, as well as affecting your mood, which can lead to mental health problems. 

What confirms Crohn’s disease?

Typically, medical imaging can be used as a diagnostic tool to confirm the diagnosis of Crohn’s. A doctor may perform an endoscopy which entails looking at the colon through a camera inserted either via your anus or mouth.9 The second type of test is a biopsy, where a small part of your colon is taken out to be examined in order to see the extent of the damage.8 Other imaging tests exist, such as chromoendoscopy, whereby a liquid dye can highlight the changes in the intestinal lining, and small intestine imaging.9 The most common test for Crohn’s is a colonoscopy, and your doctor will consult you if further tests are needed. 

Who is most likely to get Crohn’s disease?

It is important to note that the disease can occur at any age. However, it is typically more prevalent among adolescents between the ages of 20-30.10 Certain ethnic groups, including Caucasians, Hispanics, and Asians, have a higher rate of developing the disease.10  


  1. Causes of Crohn’s Disease [Internet]. Crohn's & Colitis Foundation. 2022 [cited 12 September 2022]. Available from: 
  2. Liu J, Anderson C. Genetic studies of Crohn's disease: Past, present and future. Best Practice & Research Clinical Gastroenterology [Internet]. 2014 [cited 12 September 2022];28(3). Available from: 
  3. Environmental Influences on the Onset and Clinical Course of Crohn’s Disease—Part 1: An Overview of External Risk Factors. Gastroenterology and Hepatology [Internet]. 2013 [cited 14 September 2022];9(11). Available from: 
  4. Ha F, Khalil H. Crohn’s disease: a clinical update. Therapeutic Advances in Gastroenterology [Internet]. 2015 [cited 14 September 2022];8(6):352-359. Available from: 
  5. Allman T. Crohn's disease. 1st ed. Detroit: Lucent Books; 2012. 
  6. Signs and Symptoms of Crohn’s Disease [Internet]. Crohn's & Colitis Foundation. 2022 [cited 14 September 2022]. Available from:  
  7. Langenberg D, Yelland G, Robinson S, Gibson P. Cognitive impairment in Crohn’s disease is associated with systemic inflammation, symptom burden and sleep disturbance. United European Gastroenterology Journal [Internet]. 2017 [cited 14 September 2022];5(4):579-587. Available from:   
  8. Irving P, Barrett K, Nijher M, de Lusignan S. Prevalence of depression and anxiety in people with inflammatory bowel disease and associated healthcare use: population-based cohort study. Evidence Based Mental Health [Internet]. 2021 [cited 14 September 2022];24(3):102-109. Available from:  
  9. Crohn’s Disease Diagnosis and Testing [Internet]. Crohn's & Colitis Foundation. 2022 [cited 14 September 2022]. Available from: 
  10. Overview of Crohn's Disease [Internet]. Crohn's & Colitis Foundation. 2022 [cited 14 September 2022]. Available from: 

Rebecca Dion

Master of Public Health - MPH Student, Lund University, Sweden

Interested in health promotion for children and young adults. I have been working and studying in the multicultural environments of London , Paris and more recently in Lund. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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