Understanding the causes of IBD

An interaction between genes, immunity, gut bacteria and the environment

• Genes
• Immunity
• Gut bacteria
• Environment

Why did I get the disease?

The most important question

There is no single cause. Several factors interact, so the immune system reacts too strongly and continuously to the contents of the bowel, leading to long-term (chronic) inflammation in the bowel wall.

The disease is not the result of something you did wrong, and it does not spread from one person to another.

Factors that interact

Four factors

• Genetic tendency — many genes are linked to the disease, but most patients have no one else affected in their family
• Faulty immune regulation — the inflammatory response carries on instead of settling once its job is done
• Disturbed gut bacteria — the natural balance of gut bacteria is upset in many patients
• Environment and lifestyle — such as smoking, some medicines, and the modern diet

These factors make the disease more likely, but having them does not necessarily mean you will get it.

Environmental factors linked to the disease

Environment

• Smoking — increases the risk of Crohn's disease and makes its course more severe
• Repeated use of antibiotics — especially in childhood; this has been linked to a higher risk
• The modern diet — lots of processed food and too little fibre and vegetables may be linked to a higher risk
• Urbanisation and lifestyle change — the disease is becoming more common in communities where lifestyle has changed quickly, including the Gulf region

These are associations that increase the likelihood; they do not mean that any single factor is the direct cause.

Things that do not cause the disease

Misconceptions

• Psychological stress — it does not cause the disease, but it may make you feel your symptoms more
• A particular food you ate — no specific food has been proven to directly cause the disease
• Catching it from someone else — the disease is not spread by close contact or sharing food
• Irritable bowel syndrome (IBS) — IBS does not turn into Crohn's disease or ulcerative colitis

Will my children get it?

Inheritance

Brothers, sisters and children have a higher chance of getting the disease than the general population, but the chance remains low, and most children of patients do not get the disease.

Routine genetic tests for children are not recommended. Tell your doctor if someone else in the family is affected.

What can you control?

Your role

• Stopping smoking — one of the most important steps, especially for people with Crohn's disease
• Sticking to your treatment — even when symptoms are quiet
• A balanced diet — rich in vegetables, fruit and natural foods as far as possible
• Regular follow-up — to pick up any disease activity early

Genes cannot be changed, but the course of the disease can be influenced with the right treatment and follow-up.

Causes of the disease: the summary

Key messages

• The disease results from several factors interacting, not from a single cause
• It is not infectious and it is not your fault
• No specific food, and not stress, has been proven to directly cause the disease
• Stopping smoking helps all patients, and is essential in Crohn's disease
• Treatment and follow-up help improve the course of the disease

Talk to the clinic team if:

• You have questions about inheritance and your children
• Your symptoms have changed or got worse
• You feel psychological stress affecting your life
• You smoke and want help to stop
• You are planning a pregnancy or to start a family
• You need reliable sources of information

If you have heavy bleeding, severe pain or a very high temperature, go straight to the nearest emergency department.