Crohn's is a condition in which areas of inflammation occur anywhere along the intestinal tract, especially the last segment of the small intestine (ileum) and the colon. It causes inflammation, deep ulcers and scarring to the wall of the intestine and often occurs in patches. Crohn's disease involves all layers of the intestine. In Crohn's, normal, healthy sections of bowel may lie between patches of diseased bowel. If you suspect that you have Crohn's disease, you should seek appropriate medical help without delay. Diagnosis is usually by means of colonoscopy and mucosal biopsy. Initial treatment to reduce flare-ups is administration of steroids such as prednisolone.

Symptoms include chronic diarrhoea, associated 'right sided' abdominal pain, severe fatigue, fever, weight loss, and abdominal fullness. Often the first attack seems to be like appendicitis, and many times occurs around the age of twenty. As the disease progresses, intestinal function becomes ever more impaired. Abscesses, fistulas, pockets and canals of infection can affect other organs.
The severity of the symptoms fluctuates unpredictably over time. Patients are likely to experience flare-ups in between intervals of remission or reduced symptoms.

Crohn's Disease affects approximately 55,000 people in the UK - that's about 1 in 1,000. Approximately 3,000 new cases are diagnosed each year; in 15-20% of cases there will be a family history. It is twice as common in smokers as non-smokers. Research shows that the number of people with Crohn's Disease has been rising steadily, particularly among young people. More recently, numbers have stabilised.

One of the current theories regarding Inflammatory Bowel Disease such as Ulcerative Colitis and Crohn's revolves around a particular immune system cytokine, IL-17. This cytokine was only discovered in 2006, but is found in almost all autoimmune pathologies or diseases. We have known for some time that some probiotic bacteria can help reduce the severity of the inflammation in many cases of UC, without really knowing the specific mechanism. Now it appears that researchers in Japan have discovered a potential explanation. IL-17 is a very potent pro-inflammatory cytokine, that is it causes inflammation. When it is over produced in the colon, a chronic inflammatory condition can result. Administration of Bifidobacteria inhibited IL-17 production by naturally producing IL-10, an 'anti-inflammatory' cytokine which has a ‘cancelling’ effect on IL-17.