Background

Inflammatory bowel disease (IBD) 

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Inflammatory bowel disease (IBD) is an umbrella term used to describe disorders that cause chronic inflammation of your gastrointestinal (GI) tract. The two most common forms of IBD are Crohn’s disease and ulcerative colitis.

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 Crohn’s disease (CD) is a chronic, relapsing-remitting gastrointestinal condition. It can affect any part of the GI tract, as well as causing extraintestinal manifestations in the hepato-pancreato-biliary system, skin, joints, eyes, oral cavity and bone metabolism. It affects approximately 1 in 800 people in the UK and its incidence is rising globally.

 CD is a multifactorial immune-mediated disease, causing transmural inflammation of the GI tract. The aetiological factors that cause CD are still not fully elucidated, but genetics, alterations in gut microbiota and environmental factors are known to play a role.

 In the first 5 years from diagnosis 22% of patients will require surgical intervention, rising to 70-90% during their lifetime. However, risk of surgical, endoscopic and clinical recurrence remains high. It is estimated that up to 40% of patients will have surgical recurrence within 10 years. Surgical intervention may be necessary to manage strictures, fistulae, obstruction or perforation, but is not curative.

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Ulcerative colitis (UC) is a chronic, relapsing-remitting gastrointestinal condition. It mainly affects the large intestine, also known as the colon, resulting in extensive inflammation of the GI lining and ulcer formation.  The disease affects approximately 1 in 1000 of the population.

 The pathogenesis of UC is complex and is classically thought to involve an abnormal interaction between the microbial flora, mucosal epithelial barrier, and the host immune system in susceptible individuals.

 UC typically starts in the rectum and extends proximally in a uniform manner resulting in the 3 major phenotype classifications of proctitis, left-sided, or pancolitis. Twenty to 54% of patients develop a more extensive phenotype over the course of their disease. Primary defects of the mucosa have been postulated as being important in the etiology of the disease.

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