Ulcerative Colitis and Crohn’s disease

What are Ulcerative Colitis and Crohn’s Disease?

Both conditions are forms of Inflammatory Bowel Disease (IBD).  In inflammatory bowel disease the intestines become swollen, inflamed and ulcerated. Symptoms can include pain in the abdomen, weight loss, diarrhoea (sometimes with blood or mucus) and tiredness. The symptoms will vary in severity from one person to another and may flare up or improve unpredictably. Many patients with inflammatory bowel disease experience some periods of remission, when they are free from symptoms but they are life-long diseases.


Ulcerative Colitis

Ulcerative colitis (UC) affects the inner lining (mucosa) of the colon (large bowel). Extending upwards from the rectum – the part of the bowel which lies just inside the anus. Sometimes for patients the inflammation is limited just to the rectum – this is known as Proctitis. However the inflammation can spread to variable lengths of the large bowel. Active inflammation on the left side of the colon is known as distal colitis and when the whole of the colon is affected this is termed extensive colitis. Older terms include pan-colitis or total colitis.


The most common symptoms of UC are diarrhoea, urgency (needing to rush to the toilet) bleeding from the back passage and pain in the abdomen. But the symptoms do vary from one patient to the next. To a certain extent the symptoms depend on how much inflammation there is and how much of the colon is affected by the disease. For example some patients may notice that they pass blood when they open their bowels and others may experience symptoms more in keeping with constipation than diarrhoea. Some patients can pass considerable quantities of mucus and wind when they open their bowels.  


For some people their condition can interfere with day to day life which becomes organised around visits to the toilet. This includes not only the number of times needed but the urgency that can become distressing. As symptoms are often worse in the morning, this can mean the start of the day can be quite an ordeal.


Treatment of ulcerative colitis depends on the extent and severity of the condition. Aminosalicylates (5-ASAs) are anti-inflammatory drugs and include mesalazine, olsalazine and balsalazide. These drugs are used to dampen down the inflammation within the bowel and steroids may be used if the inflammation is severe. If the inflammation is confined to the rectum (proctitis) topical treatments are the method of choice in the form of suppositories or enemas that are inserted directly into the back passage. This meaning that the medication is directed right against the inflamed part of the bowel. 5-ASAs are also prescribed to maintain remission (once the inflammation has settled) and reduce the possibility of a further flare-up. If these drugs prove to be ineffective other medication may be considered such as azathioprine or mercaptopurine.


Surgery is generally considered only in patients if their disease is not responding to medical therapy. This may follow an admission to hospital where a course of intravenous (into the vein) steroids are given and there is no response. In patients with UC surgery usually consists of removal of the whole or part of the colon (colectomy or sub-total colectomy) and in most patients it is usually possible to remove the diseased colon and rectum and construct an internal pouch (ileo-anal pouch, also known as restorative proctocolectomy) of small intestine that acts very much like the rectum.


Crohn’s Disease

Crohn’s disease affects all the layers of the bowel wall and can occur in any part of the gastrointestinal tract from mouth to the anus. The disease affects mainly young adults but can occur in younger children and sometimes starts later on in life. The most common site of inflammation is the last part of small bowel known as the terminal ileum and the first part of the large bowel. In some patients the inflammation can affect only the large bowel and this is known as Crohn’s colitis sometimes it can be difficult to distinguish it from ulcerative colitis. Rarely the mouth, oesophagus or stomach may be involved.


Crohn’s disease results in patches of inflammation in the lining of the intestine with the presence of ulcers. These ulcers can become larger and deeper with a lot of surrounding redness. This can cause the intestine to become thickened and narrowed blocking the passage of digested food. In some patients the inflammation can go deeper into the bowel wall causing a perforation or fistula to form. This allows bowel contents to leak causing abscess formation. A fistula is an abnormal channel causing a connection between two surfaces, for example between the colon and the skin. These most frequently occur around the anus.   


Symptoms vary with the site affected patients mainly complain of diarrhoea and abdominal pain. There can be blood when the last part of the large bowel is affected. The pain is usually caused by digested food or faeces building up in narrowed or inflamed areas. Sometimes these areas can become narrowed (strictured) causing a partial blockage that can cause severe, griping abdominal pain with swelling and vomiting. Other symptoms can be weight loss, fever and fatigue (tiredness) and in young children with Crohn’s a lack of appetite and malabsorption can lead to a dramatic weight loss and can have an adverse affect on their growth and development.


Treatment for Crohn’s disease depends on which part and how much of the gastrointestinal tract is affected. Active inflammation is usually treated with steroid drugs which work by reducing the swelling and the pain of inflammation. For more persistent disease immunosuppressant’s such as azathioprine or newer biologic drugs such as infliximab and adalimumab may be considered in patients when their disease has not responded to other treatments.


Due to the nature of Crohn’s disease it is not uncommon for patients to develop blockages in the intestine and if medical therapy is not working surgery may be considered. The operation is known as a resection where the section of inflamed intestine is removed and the healthy tissues are joined together. Other people may have limited areas of narrowing in the small intestine which can be surgically widened or stretched to relieve the obstruction this is called a strictureplasty. Short strictures (narrowings) may be treated endoscopically (with a camera) and dilated with a balloon.        

Extra-intestinal manifestations of IBD

A small minority of people with IBD also have extra-intestinal inflammation, possibly due to an altered immune function. The most common are listed below:

  • Inflammation of the joints
  • Inflammation of the skin
  • Inflammation of the eye
  • Inflammation of the bile ducts (Primary sclerosing cholangitis)

These conditions tend to improve with the medical treatment for your inflammatory bowel disease but in some cases require specific treatment.


What causes Ulcerative Colitis and Crohn’s disease?

The cause or causes of IBD are not yet known. Current theories suggest that IBD may be caused by an abnormal response between the immune system and intestinal bacteria, much evidence suggests that gut bacteria are different in patients with IBD and that there is a reduction in bacterial diversity (limited different types of species).


Smoking – A strong link between smoking and IBD has been found in many studies. If you have Crohn’s disease and are a smoker your Crohn’s is likely to be more severe and may be more likely to require surgery. However the situation is different in Ulcerative Colitis, some people develop UC when they gave up smoking, which is not to say that you should take up smoking.


Diet – Although there is no evidence that diet is the cause of IBD, some people do find that cutting out certain foods can lessen the chances of attacks and likewise that certain foods can exacerbate their symptoms. In Ulcerative Colitis high-fat foods can trigger diarrhoea and people with Crohns, depending on the area of disease, may have difficulty absorbing minerals and nutrients. If you have a stricture you may be advised to take a low residue diet. In Crohn’s disease there is good evidence that an exclusive elemental or polymeric diet (a special liquid only diet) is almost as effective as steroid treatment but is very restrictive and is usually reserved for children and the few highly-motivated adults who are keen to avoid steroid treatment.


Stress –is not known to be a cause of IBD but it has been proven that it can lead to increased flare-ups. Stress is part of life but learning to deal with it can make a difference. Having support from family and friends can provide positive effects on social, psychological and physical well being.


Useful links

Crohn’s and Colitis UK                      www.nacc.org.uk

Life and IBD (EFFCA)                     www.lifeandibd.org.uk

RADAR Disability Network              www.radar.org.uk

Bladder and Bowel Foundation         www.bladderandbowelfoundation.org


CORE                                           www.corecharity.org.uk


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