Crohn's Disease is a condition which causes inflammation of the lining of the digestive system, usually in the ileum or colon. The ileum is last section of the small intestine, before food moves to the large intestine, and its main purpose is to absorb nutrients. The colon or large intestine is the last part of the digestive system, and it extracts nutrients from undigested food before it is eliminated from the body. However inflammation due to Crohn's Disease can occur at any point in the digestive system. This inflammation over time can damage sections of the digestive system causing additional complications.
Conditions such as Crohn's disease or ulcerative colitis that cause inflammation of the intestines are known as inflammatory bowel disease (IBD).
The symptoms of Crohn's Disease will vary depending on how much of the colon is affected, and also depending on the level of inflammation. Symptoms can vary from mild (where the condition is a minor inconvenience) to severe cases (where the quality of life is severely affected). In severe cases, ulcers can form on the lining of the digestive system, and these can bleed and produce mucus.
Common symptoms of Crohn's Disease include abdominal pain, fatigue and bloody diarrhoea. There can also be a frequent need to go to the toilet, weight loss, loss of appetite, tiredness, fever, dehydration and anaemia. Weight loss can be caused partly by loss of appetite due to the abdominal pain and diarrhoea, and also because the inflammation can affect your ability to absorb nutrients from food.
Less common symptoms of Crohn's Disease can include high temperature or fever, nausea, vomiting, skin rashes, inflammation and irritation of the eyes, and joint pain and swelling.
The exact causes of Crohn's Disease are not known. Research suggests that genetic and environmental factors both play a part. In terms of genetics, the genes that you inherit from your parents may increase the risk of you developing Crohn's Disease. With regards to environmental factors, Crohn's Disease is most prevalent in westernised countries such as the UK, and less common in poorer parts of the world such as Africa.
Crohn's Disease is also associated with a malfunction of the immune system, where the body’s own cells attack the lining of the digestive system, causing inflammation. The body then takes this inflammation as a sign of further infection, so increasing the immune response in a vicious cycle. Some researchers believe that a viral or bacterial infection may be the trigger to cause the body’s cells to attack the digestive lining. Others believe that it is just a malfunction of the immune system, fighting an infection when no infection is actually present.
Once Crohn's Disease has been diagnosed, you will usually be referred to a gastroenterologist who will assess the severity of your condition. The severity of the Crohn's Disease is judged by how many times you are passing stools, whether those stools are bloody, whether you have symptoms of fever, how much control you have over your bladder, and your general wellbeing.
Although there is no cure for Crohn's Disease, there are a number of successful treatments which can relieve the symptoms. A variety of medications can be used to either reduce the inflammation (such as steroids, typically budesonide and prednisolone, or aminosalicylates), or to reduce the immune system response (immunosuppressants). In may cases of Crohn's Disease, hospitalisation or surgery may be required, if the syptoms cannot be controlled using medication alone. The NHS estimate that 80% of people with Crohn's Disease will require surgery at some point in their life, to remove the inflamed section of the digestive system.