Ulcerative Colitis (UC) and Crohn's Disease Fact Sheet

This information can be found on the NACC website together along with a wealth of other detail on these two conditions.


  • Together, UC and Crohn’s Disease affect about 1 person in every 400 in the United Kingdom population
  • UC and Crohn’s Disease are chronic (ongoing) conditions, which are not infectious
  • Although diagnosis can occur at any age the most common age for diagnosis is between 10 and 40
  • In both UC and Crohn’s there is a higher chance of developing either illness if you have a close relative who has the condition
  • In 10-15% of cases, UC and Crohn’s may be difficult to distinguish
  • Men and women suffer equally
  • The severity of the symptoms fluctuates unpredictably over time. Patients are likely to experience flare-ups in between intervals of remission or reduced symptoms
  • The cause or causes have not yet been identified in either illness. Both genetic factors and environmental triggers are likely to be involved

Ulcerative Colitis (UC)

  • Affects up to 120,000 people in the UK - about 1 in 500
  • Between 6,000 and 12,000 new cases are diagnosed each year

What is it?

  • UC affects the rectum and sometimes the colon (large intestine). Inflammation and many tiny ulcers develop on the inside lining of the colon resulting in urgent and bloody diarrhoea, pain and continual tiredness. The condition varies as to how much of the colon is affected
  • UC can cause inflammation in the eyes, skin and joints
  • If the inflammation is only in the rectum it is known as proctitis

Crohn's Disease

  • Affects approximately 60,000 people in the UK, that’s about 1 in 1000
  • Between 3,000 and 6,000 new cases are diagnosed each year
  • Research shows that the number of people with Crohn’s Disease has been rising steadily, particularly among young people. More recently, numbers have stabilised
  • It can affect anywhere from the mouth to the anus but most commonly affects the small intestine and/or colon. It causes inflammation, deep ulcers and scarring to the wall of the intestine and often occurs in patches
  • The main symptoms are pain in the abdomen, urgent diarrhoea, general tiredness and loss of weight. Crohn’s is sometimes associated with other inflammatory conditions affecting the joints, skin and eyes.

Source: NACC.