Inflammatory Bowel Disease

What is IBD

The term “inflammatory bowel disease” (IBD) is used to describe ulcerative colitis and Crohn’s disease collectively.

Both disorders are chronic inflammatory conditions of the wall of the gastrointestinal tract. The cause is still unknown. It is sometimes hard to identify which condition exists but as time goes by, it usually becomes clear whether the condition is Crohn’s disease or ulcerative colitis.

Ulcerative colitis

Ulcerative colitis results from an inflammation of the surface lining of the large intestine, colon. The inflammation starts in the rectum and may spread to involve the whole of the large bowel.

Crohn’s disease

Crohn’s disease results from an inflammation of the full wall thickness of the intestine. In contrast to ulcerative colitis, Crohn’s may involve any part of the digestive tract but most frequently occurs:

• In the terminal ileum, the end part of the small intestine, and is called ileitis
• In the large intestine — called Crohn’s colitis
• In both the small and large intestine — called ileo colitis

Distribution of disease:

How is inflammatory bowel disease diagnosed?

The diagnosis of inflammatory bowel disease is based on a combination of the clinical features of the illness and the results of tests that the doctor carries out.

The history of the illness and the physical examination are very helpful in raising the possibility of inflammatory bowel disease, but an accurate diagnosis needs other investigations:

• a) Sigmoidoscopy — This is an examination of the lower intestine only with an instrument, which enables the doctor to look at the lining of the bowel, and to take biopsy samples from the bowel wall. Since the lower bowel is involved in all those with ulcerative colitis and about half of those with Crohn’s disease, this is a helpful investigation for inflammatory bowel disease.
• b) Colonoscopy — Allows the lining of all the large intestine and terminal ileum to be inspected using a flexible tube inserted through the anus. Colonoscopy has reduced the need for barium enema examinations. Colonoscopy can also be used to determine how much of the large intestine is involved and the extent and severity of disease. It also has the advantage of allowing biopsies, tissue samples, to be taken from the bowel wall during the procedure.
• c) Histopathology — This is a detailed microscopic examination by a pathologist of tissue samples, biopsies, taken at the time of sigmoidoscopy and colonoscopy. Histopathology can be very helpful in confirming the diagnosis and indicating whether the inflammatory bowel disease is active or not.

How common is inflammatory bowel disease and who gets it?

• a) Incidence and prevalence — Each year, 2-9 new cases of ulcerative colitis occur per 100,000 population, the incidence. At any one time, there are 40-80 active cases per 100,000 population, prevalence.
• b) Geography — Inflammatory bowel disease occurs worldwide. It is more common in developed countries. It is uncommon in Africa, Asia and South America.
• c) Age and Sex — Inflammatory bowel disease occurs in males and females equally. Crohn’s disease can start at any age, but there is a peak between 15 and 30. Ulcerative colitis can affect infants and very young children but Crohn’s disease is rare under the age of five.
• d) In UK — IBD affects 1:400 people.

What causes inflammatory bowel disease?

• a) Genetic factors — The exact nature of the genetic factors in the development of the disease are obscure. Studies show an increased frequency of inflammatory bowel disease in related individuals.
• b) Diet — No specific dietary factors have been shown to play a role. People with Crohn’s disease eat more refined sugar and less fibre from fruit and vegetables. This could well be a result rather than a cause of the disease. Those with Crohn’s disease may be eating more refined sugar to increase their energy intake to reduce pain and discomfort.
• c) Infectious agents — There is no convincing evidence that inflammatory bowel disease is caused by viruses or bacteria. Inflammatory bowel disease is not contagious.
• d) Drugs- Studies have shown that drugs used to treat arthritis and rheumatism, NSAID’s, may precipitate attacks or relapses of inflammatory bowel disease.
• e) Smoking — Smokers are more likely to develop Crohn’s disease than non-smokers. Ulcerative colitis is a disease of non-smokers and ex-smokers.
• f) Psychogenic factors — There is no evidence that particular personality types or emotional stress cause inflammatory bowel disease. However, emotional stress may increase suffering and the severity of symptoms.

How does inflammatory bowel disease affect people?

a) Ulcerative colitis — Common symptoms of ulcerative colitis are:

• Diarrhoea
• Rectal bleeding, bleeding from the bowel
• Passage of mucus
• Abdominal pain and discomfort
• Fever
• Tiredness, loss of appetite

Symptoms and their severity depend upon the length of bowel involved and the amount of inflammation.

The majority of people with ulcerative colitis follow an intermittent course. They have episodes of relapse in which their colitis “flares up” and times of remission with complete freedom from symptoms between these episodes of attacks.

b) Crohn s disease — There are many different clinical features of Crohn’s disease as it may affect any part of the gastrointestinal tract from the mouth to anus.

Common symptoms include:

• Abdominal pain
• Diarrhoea
• Fever, malaise
• Nausea and vomiting
• Loss of appetite of weight loss
• Poor growth in children

The disease is one of relapses and remissions but a large percentage of people never experience complete remission and need continuous medical therapy to control symptoms.

How is inflammatory bowel disease treated medically?

Drug treatment is usually required for an acute attack of ulcerative colitis. Those with mild or moderate disease are usually managed as “outpatients”.

The treatment of active Crohn’s disease depends on the part of the bowel affected and on how much and how severely the bowel is involved. General treatment measures are important. Adequate rest and a nutritious diet are essential.

There are several drugs used in the treatment of inflammatory bowel disease. The aim of these drugs is to reduce the inflammation in the bowel and therefore reduce the symptoms such as diarrhoea and pain. Your doctor will prescribe the drugs suitable for you and your condition. Some drug therapy is needed to treat an acute attack, to bring it under control. They are usually tapered off and then stopped. Other drugs are used in maintenance treatment to reduce the chances of a flare-up.

What is the role of diet in inflammatory bowel disease?

Most people with inflammatory bowel disease should eat a normal diet that is adequate in all nutrients to maintain weight and promote normal growth. Paying greater attention to diet can help reduce symptoms and replace lost nutrients. An adequate intake of protein is essential for maintenance and repair of tissues and carbohydrates and an important source of energy. Vitamins, minerals such as iron, calcium and zinc, dietary fibre and water are all important to cope with your body’s needs. At times nutritional supplements may be needed. Your Doctor and/or dietician if necessary will advise you.

Continuing management of inflammatory bowel disease

As with other chronic disorders such as diabetes, asthma and arthritis, those with inflammatory bowel disease need their condition monitoring. This lets the doctor check response to treatment and determine if drug side effects have occurred. Monitoring usually consists of a combination of clinical history, blood tests and a physical examination using sigmoidoscopy or colonoscopy.

When is surgery required in inflammatory bowel disease?

A small number of people with inflammatory bowel disease require surgery. Ulcerative colitis and Crohn’s disease require different surgical management.

Are patients with IBD at higher risk of cancer?

With Crohn’s disease there seems to be a similar risk as with people of a similar age in the community.

With ulcerative colitis there can be a slight increased risk of colon cancer, particularly when the whole length of the large intestine is involved after having the disease for more than 10 years. However, because this condition requires ongoing regular surveillance any changes in the bowel lining are picked up.

Living with inflammatory bowel disease

Most people with inflammatory bowel disease lead useful, productive lives, even though they may need to take medication and may sometimes need admission to hospital. Inflammatory bowel disease is no barrier to success professionally, socially or in sport. Between bouts of their disease, most feel quite well and are relatively free of symptoms.

References:

National Association for Crohn’s and Colitis, NACC
4 Beaumont House,
Sutton Road,
St Albans,
Herts.
AL1 5HH

For further information
www.nacc.org.uk
www.corecharity.org.uk

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