About Crohn’s & Colitis

Crohn’s Disease and ulcerative colitis are Iife long gastrointestinal disorders  that commonly present themselves in children, adolescents and adulthood.

Collectively known as Inflammatory Bowel Disease (IBD), the conditions are an emerging global disease, with Australia having one of the highest prevalence in the world.   More than 80,000 Australians live with these conditions, with numbers expected to increase to more than 100,000 by 2022.

The conditions are becoming more prevalent, more severe and more complex and are being diagnosed in more and more very young patients.

During a disease flare, inflammation in the colon, rectum and gastrointestinal tract can become so severe that sufferers need to be hospitalised and/or require surgery.

The conditions are  largely unpredictable with significant variation in the degree and pattern of symptoms affecting each patient. The relapsing and chronic nature of the disorder has broader impacts on a person’s emotional, physical and social wellbeing. Patients may also develop complications that are potentially life threatening, with links between IBD and increased risks of colorectal cancer as well as the adverse side effects of treatment.


    Inflammatory bowel disease (IBD) is a medical term that describes a group of conditions in which the intestines become inflamed (red and swollen).

    Two major types of IBD are Crohn’s disease and ulcerative colitis. Ulcerative colitis affects the large intestine (colon) whereas Crohn’s disease can occur in any part of the intestines.

  • Causes of IBD

    No one knows for certain yet what causes IBD but it is believed to be a combination of genetic, environmental and immunological factors.

    Exposure to environmental triggers – possibly viruses, bacteria and/or proteins – prompts the immune system to switch on its normal defence mechanism (inflammation) against a foreign substance.

    In most people, this immune response gradually winds down once the foreign substance is destroyed. In some people (possibly those with a genetic susceptibility to IBD), the immune system fails to react to the usual ‘switch off’ signals so the inflammation continues unchecked.

    Prolonged inflammation eventually damages the walls of the gastrointestinal tract and causes the symptoms of IBD.

  • Symptoms of IBD

    IBD is a very individual disease with symptoms dependent on where the disease is located in the gastrointestinal tract and how severe the inflammation is within the affected area. Symptoms of IBD may range from mild to severe but tend to include the following:

    • abdominal cramps and pain
    • frequent, watery diarrhoea (may be bloody)
    • severe urgency to have a bowel movement
    • fever during active stages of disease
    • loss of appetite and weight loss
    • tiredness and fatigue
    • anaemia (due to blood loss)

    A small percentage of people with IBD may also experience problems outside the gastrointestinal tract including joint pain, skin conditions, eye inflammation, liver disorders, and thinning of the bones (osteoporosis).

    Although IBD is a chronic (ongoing) condition, symptoms may come and go depending on the presence and degree of inflammation in the gastrointestinal tract. When inflammation is severe, the disease is considered to be in an active stage. When inflammation is less (or absent), symptoms may disappear altogether and the disease is considered to be in remission.

    For most people with IBD, the usual course of disease involves periods of remission interspersed with occasional flare-ups.

  • Treatment of IBD

    IBD cannot be cured as yet but it can be managed effectively, especially with the use of medications to control the abnormal inflammatory response.

    Controlling inflammation allows the intestinal tissues to heal and relieves the symptoms of abdominal pain and diarrhoea. Once symptoms are under control, continued use of medications helps to reduce the frequency of flare-ups and maintain remission.

    Medications most commonly used to manage IBD include aminosalicylates, corticosteroids, immunomodulators, biological agents and antibiotics.

  • IBS is not IBD

    Inflammatory bowel disease (IBD) is different from irritable bowel syndrome (IBS)

    IBD is an autoimmune disorder. An autoimmune disorder occurs when a person’s immune system mistakenly attacks their own body tissues.- in this case, the gastrointestinal tract. In many ways IBD has more in common with other autoimmune disorders – such as rheumatoid arthritis (which affects the joints), psoriasis (which affects the skin) and lupus (which affects the connective tissue) – than IBS.

    Unlike IBD, IBS does not cause inflammation, ulcers or other damage to the bowel. The digestive system looks normal but doesn’t work as it should. Factors such as emotional stress, infection and some foods can aggravate the condition. Treatment options include dietary modifications and stress management.

    People with IBD may also have IBS but it is important to note that these are two separate conditions.


    Crohn's Disease Diagram

    Crohn’s disease can involve any part of the gastrointestinal tract from the mouth to the anus but most commonly affects the small intestine and/or the colon. There may be areas of healthy intestine between areas of diseased intestine. Within a diseased section, Crohn’s disease can affect all layers of the intestinal wall (i.e. not just the lining). This can lead to the development of complications that are specific to this condition:

    • strictures (intestinal obstruction or narrowing of the intestinal wall)
    • abscesses (boils) and skin tags (swollen lumps or ‘flaps’ of thickened skin occurring just outside the anus)
    • fistulae (abnormal channels connecting different loops of intestine to itself or to other body organs)
    • fissures (ulcerated tears or cracks in the lining of the anal canal) malabsorption and malnutrition


    In some cases, surgery may be required to correct the complications of Crohn’s disease or to remove diseased portions of the gastrointestinal tract (resection). Surgical resection is an important decision that needs to be taken in full consult with your clinical team as it is not a cure. Even if diseased parts of the intestines are removed, inflammation can re-appear in other areas.


    Smoking is believed to worsen the course of Crohn’s disease

    Smoking increases the need for surgery and medications, can make the disease more active and may prevent the induction of remission. After surgery for Crohn’s disease, the condition may recur sooner, and often more severely in smokers than in non-smokers. If you have Crohn’s disease and you smoke, it is important that you stop immediately.


    Crohn’s disease in the small intestine can impair the digestion and absorption of essential nutrients from food.

    During active stages of disease, many people also try to avoid eating in order to prevent further symptoms. This worsens the tiredness and fatigue and eventually leads to weight loss.

    A well-balanced and nutritious diet is essential for anyone with Crohn’s disease in order to prevent malnutrition and maintain good health. And it is even more so for growing children and adolescents who may experience delayed growth or pubertal development in the absence of adequate nutrition.


    Ulcerative celitis

    In ulcerative colitis, inflammation occurs on the lining (mucosa) of the large intestine or colon.

    The inflammation is usually located in the rectum and lower colon but may involve other parts of the colon and sometimes even the entire colon. Tiny open sores or ‘ulcers’ form on the surface of the lining and these may bleed.

    The inflamed lining also produces a larger than normal amount of intestinal lubricant or mucus which sometimes contain pus. Inflammation in the colon reduces its ability to reabsorb fluid from the faeces which causes diarrhoea. Inflammation in the rectum can lead to a sense of urgency to have a bowel movement.



    Most people with ulcerative colitis (80-90%) respond well to treatment and never develop any complications. In more severe cases where inflammation has penetrated deeper into the walls of the colon, serious complications may arise. These include:

    • profuse bleeding from deep ulcers
    • perforation (rupture) of the colon
    • fulminant colitis/toxic megacolon (partial or full shutdown of normal intestinal contractions).

    These complications can occur over a short period of time and usually require immediate medical attention.



    In people with severe disease that is not responding adequately to medication or in those with long-standing disease (>10 years duration) who are at higher risk of colorectal cancer, surgical removal (resection) of the colon may be the most appropriate long-term solution.

    Surgical resection eliminates the symptoms of ulcerative colitis and the need for ongoing use of medications to control inflammation. This can greatly enhance quality of life.

    Surgery for ulcerative colitis generally involves removing the large intestine and creating a pouch from the end of the small intestine which is then joined directly to the anus. Alternatively, the end of the small intestine can be redirected to empty into a bag attached to an opening (stoma) on the outside of the abdomen.


    Diet & Nutrition

    Although there is no clinical evidence to suggest that specialist diets benefit persons with ulcerative colitis, good nutrition is essential to the healing process.

    When disease is active, many people lose their appetite or try to avoid eating in order to prevent further symptoms. Lack of adequate nutrition worsens the tiredness and fatigue and eventually leads to weight loss.

    Children with ulcerative colitis may fail to develop or grow properly, particularly if they have long periods of active disease and/or receive frequent or prolonged treatment with high doses of corticosteroids.


    The diagnosis of Crohn’s disease or ulcerative colitis is sometimes delayed as the same symptoms can occur with other diseases. It is usually necessary to exclude diseases such as bowel infections or irritable bowel syndrome.

    Blood tests are useful to look for anaemia (low blood count) and to measure the severity of inflammation. They can also detect vitamin or mineral deficiencies. A faeces (bowel motion) specimen may be required to exclude infection.

    Most people require an examination of part of the bowel, either by direct inspection through a flexible tube inserted through the back passage (colonoscopy or sigmoidoscopy) or mouth (gastroscopy), or by x-rays, include CT scan and barium small bowel series (where dye is swallowed and x-rays taken). There is no one test that can reliably diagnose all cases of IBD, and many people require a number of tests.

  • Crohn's disease

    Crohn’s disease is suspected in people who have been experiencing symptoms such as abdominal pain, diarrhoea and weight loss that have lasted for weeks or months. Because there is no single test that can establish the diagnosis of Crohn’s disease with certainty, and because Crohn’s disease often mimics other conditions, it may take time and several investigations to arrive at the correct diagnosis.

  • Ulcerative colitis

    Whenever a person has a history of bleeding from the rectum – either with or without diarrhoea and abdominal pain – one of the conditions suspected as a possible cause of the symptoms is ulcerative colitis. Investigations are then carried out to differentiate between other diseases known to cause rectal bleeding (e.g. Crohn’s disease or colorectal cancer) and to arrive at what is called a ‘definitive diagnosis’.

  • IBD unclassified

    Sometimes patients present with feature of both ulcerative colitis and Crohn’s disease and it is impossible to distinguish between the conditions. In this case they will receive a diagnosis of IBD unclassified (IBDU – previously known as indeterminate colitis). About 10-15 per cent of people diagnosed with inflammatory bowel disease are initially given a diagnosis of IBDU. Although ulcerative colitis and Crohn’s disease share some similarities, there are some important differences which help doctors identify the most appropriate treatment for each condition.


    The major goals of treatment in IBD are:

    • to relieve symptoms
    • to achieve remission (absence of symptoms)
    • to maintain remission
    • to improve quality of life

  • Medications

    Medications are almost always the ‘first line’ treatment strategy in persons with IBD. They work by reducing the inflammation and allowing the intestines to heal.

    At present, the medications used to treat inflammation in IBD belong to five main categories:

    • aminosalicylates
    • corticosteroids
    • immunomodulators
    • biological agents
    • antibiotics
  • Maintaining treatment

    Because IBD is a chronic condition, many people will need to take medications for long periods of time, either to bring the disese under control or to maintain remission once the symptoms have disappeared.

    It’s important to take your medications exactly as prescribed, even if you’re feeling well.

    Stopping your medication can result in a flare-up of symptoms or lead to other problems, sometimes even months later.

    Always consult with your clinical team before stopping any medication.

  • Surgery

    Over time, some people no longer respond to medications, while others may have extensive and severe disease that cannot be controlled by medications alone. In these cases, surgery may be the best option to lead a healthier and more active lifestyle.

More information is available in The Inside Story: A Toolkit for Living Well with IBD, available in the Member’s Only section of the website.

For more information on IBD check out the Living with IBD section of our website