WeAreCrohns.org - The Social Support Network for People Living with Crohn's Disease and Colitis

Crohn's Disease

Published by Bupa's health information team, February 2008

What is Crohn's disease?

Crohn's disease is due to inflammation of the wall of your bowel. It can affect any part of your digestive system, from your mouth down through your stomach and bowel to your anus. However, it's most common in your small bowel or the first part of your large bowel. It may affect more than one section leaving unaffected areas in-between.

If you have Crohn's disease, you will have inflammation and swelling in affected areas of your bowel and ulcers may form. These are raw areas of the bowel lining which can bleed. Your bowel wall will be thickened and this may cause blockages.

The areas of the bowel commonly affected by Crohn's disease

Symptoms

Crohn's disease is a chronic condition. This means that it lasts a long time, sometimes for the rest of the affected person's life. The term chronic refers to time, not to how serious a condition is. Crohn's disease is characterised by flare-ups of symptoms. These alternate with periods of no symptoms at all - this is called remission. Usually there is no obvious trigger for the symptoms coming back (a relapse). When you have symptoms, the disease is said to be active. Symptoms include:

• diarrhoea - it may contain blood, pus or mucus
• a painful and swollen abdomen (tummy)
• loss of appetite
• weight loss
• fever
• rectal bleeding - this may lead to anaemia (a condition when you have too few red blood cells or not enough haemoglobin in your blood)
• tears, ulcers or abscesses (pus-filled areas) around your anus

Active Crohn's disease may cause other problems such as:

• mouth ulcers
• joint pain
• eye inflammation
• rashes
• ulcers on your skin
• fertility problems and, in women, an increased risk of miscarriage

Complications

With severe, long-term inflammation, you may develop complications. These include:

• a fistula - an abnormal connection between two parts of the body, most commonly between your bowel and your skin
• an abscess in your abdomen
• a stricture (narrowing of the bowel) - this can be caused by scar tissue that builds up after inflammation and may block your bowel
• a slightly increased risk of developing bowel cancer if you have had Crohn's colitis (Crohn's disease of the colon - your colon is part of your large bowel) for more than eight to 10 years

Causes

The exact reasons why you may develop Crohn's disease are not fully understood at present. However, it's thought that you are more likely to have Crohn's disease if your immune system (your body's defence system) overreacts to bacteria within the bowel leading to ongoing inflammation. Crohn's disease tends to run in families and researchers have identified genes associated with it.

Certain lifestyle factors, such as smoking, mean you are more likely to develop Crohn's disease. The role of diet in causing Crohn's disease isn't fully understood. However, it's possible that you are more likely to develop the condition if you eat a diet that is high in sugar and low in fibre.

Diagnosis

Your GP will ask about your symptoms and examine you. He or she may refer you to a gastroenterologist, a doctor specialising in conditions that affect the digestive system. You may have further tests including:

• blood tests
• faeces (stool) tests
• sigmoidoscopy and/or colonoscopy - you will be sedated and a thin telescope inserted through your anus and into your bowel to view the lining. If any areas look affected by Crohn's disease, a small sample of your bowel lining may be taken - this is a biopsy and will be sent to a laboratory for testing
• X-rays to provide images of your large and small bowel
• barium enema X-ray - this involves placing a fluid containing barium (a substance which shows up on X-rays) into your bowel via the rectum. X-ray images of your abdomen then show the inside of your bowel more clearly
• barium meal X-ray - this involves swallowing a drink containing barium. X-ray images of your abdomen then show the inside of your bowel more clearly
• CT scans (these use X-rays to make a three-dimensional picture of your bowel), MRI scans (using magnets and radiowaves to produce images of the inside of your body) and ultrasound may also be useful

You won't need to have a general anaesthetic for these tests and they are usually carried out as out-patient procedures. This means you have the test in hospital, but you won't need to stay overnight.

Diet

If you have Crohn's disease it's important that you eat a healthy, balanced diet with a high fibre content, unless you are prone to blockages. This is especially true when your symptoms flare up, as you will need to replace lost nutrients, although you may not feel like it. If you can eat a normal diet, you should continue to do so. However, you may find that certain foods disagree with you or that you need to eat more of particular types of food such as starchy carbohydrates (eg potatoes, bread and pasta).

When your Crohn's disease is active, your doctor may recommend that you have a liquid diet, made up of simple forms of protein, carbohydrates and fats. This is called an elemental diet and is commonly used to treat children.

Surgery

You may need surgery to treat complications or if medicines aren't controlling the disease. Your surgeon will aim to remove as little of your bowel as possible and expand any parts that have become narrowed.

Living with Crohn's disease

Some people with Crohn's disease have frequent flare-ups, whereas others have only one or two attacks during their lifetime. Flare-ups are unpredictable, but with good management your symptoms can be controlled. You are likely to be able to enjoy a normal lifestyle.