Crohn's disease - At a glance

This page offers an overview of Crohn's disease. Use the menu on the left-hand side to discover more.

Crohn's disease

  • Is one of a group of conditions known as inflammatory bowel diseaseA group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis.
  • Can affect any part of the digestive system, most commonly the small intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus. and the colonThe large intestine.
  • Causes inflammationThe body’s response to injury. of the intestines that is patchy and extends through the entire thickness of the intestinal wall
  • Is classified according to the part of the gastrointestinal tractThe gut, which begins at the mouth and ends at the anus. affected
  • Is caused by a combination of environmental and geneticRelating to the genes, the basic units of genetic material. factors
  • Is more common in people who smoke
  • Inflammation may be triggered by substances in the environment called antigens, which may come from bacteriaA group of organisms too small to be seen with the naked eye, which are usually made up of just a single cell., chemicals or pollen
  • Is more common in North America and northern Europe, and is less common in Asia or Africa
  • Is usually diagnosed in people who are in their 20s and 30s, but can occur at any age
  • May be associated with a diet high in meat and fatty and sugary foods, while vegetables, fruits, olive oil, fish, and fibre may reduce this risk
  • May be associated with some medications such as antibioticsMedication to treat infections caused by microbes (organisms that can't be seen with the naked eye), such as bacteria. and nonsteroidal anti-inflammatoryAny drug that suppresses inflammation drugs
  • Has been linked to infectionInvasion by organisms that may be harmful, for example bacteria or parasites. with mycobacterium avium subspecies paratuberculosis.

Symptoms and signs

Crohn's disease is characterized by periods of good health, called remission, interrupted by symptomatic episodes, known as flare-upsTerm to describe episodes when the symptoms of a condition worsen.. The symptoms vary from person to person and may include:

  • Abdominal pain
  • Diarrhoea, with or without bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid.
  • Bloating
  • Nausea and vomiting
  • Tiredness
  • Weight loss and loss of appetite
  • Sores around the anusThe external opening of the back passage, the rectum.
  • Rarely, inflammationThe body’s response to injury. of the eyes, skin and joints.

Complications

Crohn's disease can be associated with a number of complications:

  • Strictures - narrowing of the intestines caused by inflammationThe body’s response to injury. and scarring that can cause intestinal obstruction, pain and constipation
  • Fistulae - abnormal channels that develop between two parts of the body, for example, between an inflamed part of the intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus. and another part of the intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus.
  • Abscesses - local infections resulting in walled-off collections of pus.

Other complications may include:

  • Acute dilation of the gastrointestinal tractThe gut, which begins at the mouth and ends at the anus.
  • Perforation of the gastrointestinal tractThe gut, which begins at the mouth and ends at the anus.
  • Toxic megacolon - rapid widening of the colonThe large intestine., with abdominal pain and distension
  • Severe bleeding.

Tests and diagnosis

There is no single test for Crohn's disease. Some simple initial tests may include:

  • Blood tests - to assess liverA large abdominal organ that has many important roles including the production of bile and clotting factors, detoxification, and the metabolism of proteins, carbohydrates and fats. function and look for anaemiaA reduced level of haemoglobin, which carries oxygen in the blood. Anaemia causes tiredness, breathlessness and abnormally pale skin., inflammationThe body’s response to injury., infectionInvasion by organisms that may be harmful, for example bacteria or parasites., antibodiesSpecial proteins in the blood that are produced in response to a specific antigen and play a key role in immunity and allergy. and bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. chemical and mineral deficiencies secondary to diarrhoeaWhen bowel evacuation happens more often than usual, or where the faeces are abnormally liquid.
  • Stool tests - to look for bacterial infectionInvasion by organisms that may be harmful, for example bacteria or parasites. or inflammationThe body’s response to injury. in the gastrointestinal tractThe gut, which begins at the mouth and ends at the anus..

Further tests may include:

  • Sigmoidoscopy, which examines the lower part of the colonThe large intestine., or colonoscopyExamination of the colon and rectum with a colonoscope, an imaging instrument that is inserted through the anus., which examines all of the large bowel. A biopsyThe removal of a small sample of cells or tissue so that it may be examined under a microscope. The term may also refer to the tissue sample itself. is sometimes taken at the same time
  • Wireless capsule endoscopyExamination of the inside of the body using a tube equipped with a light source and either a small camera or an optical system. - for examination of the small intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus.
  • Abdominal X-rays (sometimes using barium)
  • Ultrasound scan
  • CTA scan that generates a series of cross-sectional X-ray images. scan
  • MRIAn abbreviation for magnetic resonance imaging, a technique for imaging the body that uses electromagnetic waves and a strong magnetic field. scan
  • White bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. cellThe basic unit of all living organisms. scan (also called scintigraphy).

Choosing treatments

A number of therapeutic options are available. Crohn's disease can be treated with a combination of:

  • Nutritional therapy
  • Medication
  • Possibly surgery.

Nutritional therapy

  • Is an essential part of the treatment of Crohn's disease
  • Can prevent or delay the need for medication
  • Involves identifying and avoiding the foods that provoke symptoms
  • May also include vitamin and mineral supplements.

It is important to maintain a good fluid intake and eat a well-balanced diet.

Medication

The five classes of medications that are used to treat Crohn's disease are listed below. With the exception of antibioticsMedication to treat infections caused by microbes (organisms that can't be seen with the naked eye), such as bacteria., all have an anti-inflammatoryAny drug that suppresses inflammation action.

  • Aminosalicylates
  • Corticosteroids
  • Immunosuppressants
  • Biological therapies
  • Antibiotics - to treat any infectionInvasion by organisms that may be harmful, for example bacteria or parasites..

Surgery

Surgery is sometimes needed when symptoms cannot be managed by medication and nutritional therapy alone. Procedures that may help include:

  • Strictureplasty or balloon dilationThe use of a balloon to open up a narrowing, or stricture, in the body. - both of these procedures may be used to relieve strictures
  • Resection - removal of part of the intestines
  • Total colectomyThe surgical removal of the colon. - removal of the entire large intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus.
  • Proctocolectomy - removal of the rectum as well as the entire large intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus.
  • Ileostomy or colostomySurgery that involves bringing part of the large intestine through the abdominal wall, through an opening called a stoma. Faeces are collected by a bag worn over the hole. - passage of the intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus. through the abdominal wall to an ostomy bag, which waste is discharged into. This is usually needed when the rectum is removed
  • Surgery for abscesses and fistulae.

Complications of surgery may include:

  • Poor wound healing
  • Infection
  • Adhesions
  • Leak from anastomosis, where two sections of healthy intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus. have been joined together after the removal of a problematic section of intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus..

The future

Outlook

  • The course and severity of the disease varies from person to person
  • Crohn's disease is very mild in about 50 per cent of patients, although it can be more severe in others
  • The most common pattern is to have a period of good healthy, interrupted by episodes when the symptoms get worse that are known as flare-upsTerm to describe episodes when the symptoms of a condition worsen. or relapses
  • Although there is no cure, Crohn's disease can improve dramatically with treatment.

Living with Crohn's disease

A team of healthcare professionals are there to help you to learn how to live with Crohn's disease.

  • Specialist nurses assist with all kinds of issues, such as stoma and post-operative care
  • Dieticians can offer invaluable advice
  • Your doctor will make sure that you get the most from your treatment regime.

Finding ways to maintain your independence will go a long way in helping you to stay positive. Many people with Crohn's disease lead normal, active lives, studying, having careers and raising families.

On the horizon

There are many new developments in treatment options currently in progress around the globe, and ongoing clinical trials invite patient participation to help with new research.