Pathology of the large bowel

Question 1

What causes diverticular disease?

Answer 1

Related to low fibre diet and increased intralumenal pressure
Symptoms only if complicated

Question 2

What is the aeitology of ischeamia of the large bowel?

Answer 2

• CVS disease
• Atherosclerosis of mesenteric vessels
• A.Fibrillation
• Shock
• Embolus
• Vasculitis

Question 3

Describe some of the histological terms to describe ischeamic colitis?

Answer 3

‘withering of crypts’
‘pink smudgy lamina propria’
‘fewer chronic inflammatory cells’

Question 4

Who is most susceptible to ischeamic colitis?

Answer 4

elderly patients

Question 5

What are the complications fo ischeamic colitis?

Answer 5

Massive bleeding
Rupture
Stricture

Question 6

Describe antibiotic-induced “Pseudomembranous” colitis?

Answer 6

Patients on broad spectrum antibiotics
Clostridium Difficile selected out
Toxin A and B  attack endothelium and epithelium
Massive diarrhoea and bleeding
Treat with Flagyl/Vancomycin
May need colectomy and may be fatal

Question 7

Describe Collagenous colitis?

Answer 7

Thickened basement membrane - thick band of collagen
Normal is between 2-3 microns
Disease is patchy
Associated with intraepithelial inflammatory cells
No chronic architectural changes

Question 8

What is the histological appearance of coeliac disease?

Answer 8

Increase in epithelial lymphocytes with normal crypt architecture

Question 9

Describe Lymphocytic colitis?

Answer 9

No chronic architectural changes in crypts
Intraepithelial lymphocytes are raised
No thickening of basement membrane

Question 10

Describe Radiation colitis?

Answer 10

Iatrogenic
Chronic active or inactive colitis
Telangectasia - widened blood vessels
Bizarre stromal cells, bizzarre vessels
May be other complications of immunosuppression if also on chemotherapy

Question 11

What is acute (infectious) colitis?

Answer 11

Infection

Rarely Drugs, ischaemia, endoscopy prep.