GI: Inflammatory Bowel Disease

Question 1

What are the causes of inflammatory bowel disease?

Answer 1

Begins with a genetic predisposition then there is thought to be an immune trigger
Trigger is idiopathoc but possibly antibiotics, infection, smoking, diet

Question 2

Where in the GI does crohn’s and ulcerative colitis affect?

Answer 2

Crohn’s: anywhere from mouth to anus - usually the ileum is involved and usually there is rectal sparing. (skip lesions)
Ulcerative colitis: begins in rectum and extends to involve anywhere in the large bowel (continuous)

Question 3

What problems can pts experience outside of the GI tract?

Answer 3

MSK pain such as arthritis (50%)
Skin problems such as tender red lumps, psoriasis (30%)
Eye problems (5%)

Question 4

How does Crohn’s present?

Answer 4

Loose non bloody stools - area of absorption inflamed so there is a large osmotic load that draws in water
Weight loss - not absorbing nutrients
Right lower quadrant pain - terminal ileum

Question 5

What is the pathology of Crohn’s?

Answer 5

There are discrete superficial ulcers and deeper ulcers - transmural inflammation leads to thickening of the bowel wall and narrowing of the lumen.
There is cobblestone appearance - oedema surrounded by ulceration
Skip lesions
Can get fistulae
Perinal disease

Question 6

What is the microscopic appearance of crohns?

Answer 6

There is granuloma formation which is a strong indicator of crohns

Question 7

How would you investigate crohns?

Answer 7

• Bloods to test for anaemia
• CT and MRI scans to look for bowel wall inflammation, obstruction and extramural problems
• colonoscopy + biopsy
• barium enema less used

Question 8

How does ulcerative colitis present?

Answer 8

Bloody, mucousy, loose stools
Weight loss
Mild lower abdo pain

Question 9

What is the pathology of UC?

Answer 9

Chronic inflammation of lamina propria
Get crypt abscesses
Decreased goblet cells so lose protective mucus
Loss of haustra - lead pipe colon 
Continuous 
Mucosa is friable - bleeds on contact

Question 10

What is the microscopic appearance of UC?

Answer 10

Crypt abscesses with lots of inflammatory cells

Question 11

How would you investigate UC?

Answer 11

Bloods to test for anaemia 
Stool cultures
Abdo xrays 
CT/MRI (less useful for UC)
Colonoscopy

Question 12

How is inflammatory bowel disease treated?

Answer 12

Medical:
Aminosalicylates for flares and remission
Corticosteroids to reduce inflammation - flares only
Immunomodulators to maintain remission

Surgical:
Crohn’s remove very bad areas (not curative)
UC remove total large intestine (curative)