What are the two major forms of IBD?
What environmental factors are associated with the development of IBD?
What is thought to be the primary cause of IBDs?
Inappropriate immune response against the gut flora in a genetically susceptible individual
How much does smoking increase the risk of developing IBD?
3-4x the risk
What is ulcerative colitis?
Relapsing/Remitting inflammaotyr disorder of the colonic mucosa. It may affect the rectum, or extend to involve part of the colon, or the entire colon. It never spreads proximal to the ileocaecal valve (except for backwash ileitis)
What are the main sites the ulcerative colitis occurs?

What are the pathological features of UC?
What distinguishes UC from Crohn’s Pathologically?
What are the pathological features of Crohn’s Disease?
Which IBD does skip lesions occur in?
Crohn’s - areas of unaffected bowel between areas of active disease
Which IBD does backwash ileitis occur in?
UC - usually in pancolitis
What is the difference in terms of the affected bowel between Crohn’s and UC?
Which IBD produces granulomas?
Crohn’s
Which type of IBD tends to fistulate more commonly?
Crohn’s
Which type of IBD are more at risk of cancer?
UC
Why does the bowel wall thicken in Crohn’s?
Due to oedema and fibrosis
What are symptoms of UC?
Episodic attacks
What signs may be present in someone with UC?
May be none. If presenting during an attack:
Extraintestinal signs (chronic)
What extraintestinal signs may be seen in IBD?
What is the following seen in?
Pyoderma gangrenosum
What is the following?
Erythema nosodum - A skin disorder of acute onset with eruption of red, tender nodules and plaques, predominantly over the lower extremities, especially the extensor surfaces. It is a form of panniculitis
What is the mechanism behind erythema nodosum?
In theory, immune complexes form after exposure to an antigen and are deposited in venules around areas of subcutaneous fat and connective tissue. The subsequent inflammation causes the lesions.
Why the lesions appear so frequently on the shins has not been explained - suggested that a combination of a relatively meagre arterial supply combined with gravitational effects on venous system gravitational favour deposition in that area
What are causes of the following?

What is the following?
Clubbing