Key Differences in IBD

Question 1

Describe the key differences between the features of Crohns & UC.

Answer 1

Crohns

• Diarrhoea usually non-bloody
• Weight loss more prominent
• Upper gastrointestinal symptoms, mouth ulcers, perianal disease
• Abdominal mass palpable in the right iliac fossa

Ulcerative Colitis

• Bloody diarrhoea more common
• Abdominal pain in the left lower quadrant
• Tenesmus (recurrent inclincation to evacuate ones bowels)

Question 2

Describe the key differences between the extra-intestinal features of Crohns & UC.

Answer 2

• Crohns
  
  • Gallstones are more common secondary to reduced bile acid reabsorption
• UC
  
  • Primary sclerosing cholangitis more common.

Question 3

Describe the key differences between the pathology of Crohns & UC.

Answer 3

Crohn’s

• Lesions may be seen anywhere from the mouth to anus
• Skip lesions may be present

UC

• Inflammation always starts at rectum and never spreads beyond ileocaecal valve
• Continuous disease

Question 4

Describe the key differences between the histology of Crohns & UC.

Answer 4

Crohns

• Inflammation in all layers from mucosa to serosa
• Increased goblet cells
• Granulomas

UC

• No inflammation beyond submucosa (unless fulminant disease) - inflammatory cell infiltrate in lamina propria
• Neutrophils migrate through the walls of glands to form crypt abscesses
• Depletion of goblet cells and mucin from gland epithelium
• Granulomas are infrequent

Question 5

Describe the key differences between the radiology & Endoscopy in Crohns & UC.

Answer 5

Crohn’s

• Endoscopy: Deep ulcers, skip lesions - ‘cobble-stone’ appearance
• Radiology: Small bowel enema
  
  • ​High sensitivity and specificity for examination of the terminal ileum.
  • Strictures: ‘Kantor’s string sign’
  • Proximal bowel dilation
  • ‘Rose thorn’ ulcers
  • Fistulae

UC

• Endoscopy: Widespread ulceration with preservation of adjacent mucosa which has the appearance of polyps (‘pseudopolyps’)
• Radiology: Barium enema
  
  • Loss of haustrations
  • Superficial ulceration, ‘pseudopolyps’
  • Long standing disease: colon is narrow and short -‘drainpipe colon’

Question 6

Describe the key differences between the the management of Crohns & UC.

Answer 6

Crohn’s Disease

• Inducing Remission
  
  • First line - glucocorticoids
  • Second line - Mesalazine (5-Aminosalicates)
• Maintaining Remission
  
  • Stop smoking
  • First line - azathioprine or mercaptopurine
  • Second line - Methotrexate

UC

• Inducing Remission
  
  • First line - Rectal (topical) aminosalicylates or steroids
  • Second line - Oral prednisolone
• Maintaining Remission
  
  • Oral aminosalicylates e.g. mesalazine
  • Azathioprine and mercaptopurine