Crohn's disease (CD) is an inflammatory and chronic condition of the digestive tract that progresses with flare-ups and is part of the so-called inflammatory bowel diseases. The inflammation can affect different areas of the digestive tract depending on the person. It is of unknown cause, although it is believed to be due to a combination of environmental, immune, and genetic factors. Its global prevalence is estimated at 0.4%.
Crohn's disease
The exact causes and triggers of Crohn's disease are unknown. Research shows that it may result from a combination of environmental, immune, and microbiological factors in genetically susceptible individuals. Among the most important risk factors are:
- Age: CD can develop at any age, but it usually starts during youth. Most people develop it before the age of 30.
- Ethnic origin: it is more common in people of Caucasian origin and Ashkenazi Jewish descent, although it can affect people of any ethnicity.
- Smoking: it is the most important controllable risk factor associated with CD. Additionally, smoking is also associated with a more severe course of the disease.
- Nonsteroidal anti-inflammatory drugs. They can cause inflammation of the intestines, which can worsen the disease.
- High-fat diet, which can increase the risk of developing the disease.
Symptoms
Crohn's disease typically presents with active periods (flare-ups) alternating with asymptomatic phases, although some individuals experience continuous symptoms despite treatment. These symptoms vary depending on the affected area of the intestine, but usually include the following:
- Diarrhea lasting more than 6 weeks, often with blood.
- Abdominal pain and weight loss.
- Fatigue and general malaise.
- Joint pain.
- Development of perianal fistulas.
- Inflammation of other regions such as the skin, joints, or liver.
- Kidney stones.
- Anemia.
- Growth retardation when it starts in children.
Some research suggests that stress can worsen or even trigger the appearance of symptoms. Additionally, in some people, certain foods may also worsen the symptoms.
Prevention
Prevention of the development of Crohn's disease is not possible because the exact causes of its onset are unknown. However, it is possible to act on certain risk factors that influence its development and worsen the condition, such as smoking. It has been shown that smoking increases the risk of developing this disorder and also increases the risk of complications in those who suffer from the disease.
In patients diagnosed with CD, there are therapies that can help significantly reduce their signs and symptoms and may even achieve some remission of the disease. In addition to available pharmacological and surgical treatments, there are actions that can help prevent a flare-up or reduce symptoms:
- Avoid carbonated beverages.
- Avoid high-fiber foods.
- Drink more fluids.
- Eat small amounts of food more frequently.
- Keep a food diary to help identify those that may cause problems.
Number of observed variants
13.5 million variants
Number of risk loci
104 loci
Genes analyzed
Bibliography
de Lange KM, Moutsianas L, Lee JC, et al. Genome-wide association study implicates immune activation of multiple integrin genes in inflammatory bowel disease. Nature Genetics. 2017 Feb;49(2):256-261.
National Institute of Diabetes and Digestive and Kidney Diseases (NIH) [April 2022]