Bowel Ischaemia and Colitis

Question 1

What are the different types of bowel ischaemia?

Answer 1

Acute or chronic mesenteric ischaemia

Ischaemica colitis

Question 2

What causes acute mesenteric ischaemia?

Answer 2

Thrombo-embolus (arterial/venous)

Question 3

What happens when there is a mesenteric thrombo-embolus?

Answer 3

Small bowel dies 
Colon lives (marginal artery)

Question 4

What is the epidemiology of acute mesenteric ischaemia?

Answer 4

> 50

Thrombotic risk factors

Question 5

What are thrombotic risk factors?

Answer 5

AF
Hx of MI, AAA
Hypotension
Hypercoagulability 
Infection or venous trauma

Question 6

How does acute mesenteric ischaemia present?

Answer 6

Moderate-severe colicky or constant and poorly localised pain out of proportion to physical signs

Question 7

What are investigations for acute mesenteric ischaemia?

Answer 7

FBC, AXR, angiography, CT, ECG

Question 8

What are treatment options for acute mesenteric ischaemia?

Answer 8

Papaverine
Thrombolytics
Heparin
Angioplasty
Embolectomy
Resect if gangrene develops

Question 9

What causes chronic mesenteric ischaemia?

Answer 9

Atheroscleoris

Question 10

How does chronic mesenteric ischaemia present?

Answer 10

Postprandial pain (moderate-severe colicky or constant poorly localised pain)
Weight loss
Food fear

Question 11

What are risk factors for chronic mesenteric ischaemia?

Answer 11

Smoking
Hypertension
Diabetes
Hyperlipidaemia

Question 12

What are investigations for chronic mesenteric ischaemia?

Answer 12

FBC, LFTs, U+Es, CXXR, arteriography, mesenteric duplex USS

Question 13

How do you treat chronic mesenteric ischaemia?

Answer 13

Surgery (e.g. trans-aortic endarterectomy or bypass)

Question 14

What is ischaemic colitis?

Answer 14

inflammation and injury of the large intestine result from inadequate blood supply

Question 15

What are causes ischaemic colitis?

Answer 15

Thrombus/Embolus
Arrhythmias
Atherosclerosis

Question 16

Ischaemic colitis typically affects the ___ and ______ arteries

Answer 16

middle and left colic

Question 17

Ischaemic colitis is more common in?

Answer 17

Elderly

Question 18

How do investigate ischaemic colitis?

Answer 18

ABG (metabolic acidosis)
AXR
Colonoscopy
CT colon

Question 19

How do you treat ischaemic colitis?

Answer 19

Bowel rest
Conservative management
Abx
Surgery

Question 20

What are complications of bowel ischaemia?

Answer 20

Resolution, fibrosis, stricture, chronic ischaemia
Angina of the gut
Obstruction
Gangrene, perforation, peritonitis, sepsis
Death

Question 21

What are the different types of colitis?

Answer 21

Antibiotic-induced Pseudomembranous Colitis
Collagenous colitis
Radiation Colitis
Acute (infective colitis)

Question 22

What is the gross appearance of antibiotic-induced pseudomembranous colitis?

Answer 22

Patchy yellow membranous exudate on mucous surface

Question 23

What is the microscopic appearance of antibiotic-induced pseudomembranous colitis?

Answer 23

Explosive fibropurulent exudate on surface

Explosive lesions of mucosa

Question 24

What causes antibiotic-induced pseudomembranous colitis?

Answer 24

C. diff (patients on broad-spectrum antibiotics)

Question 25

What is the mechanism of action by which C. diff causes colitis?

Answer 25

Toxin A and B attack endothelium and epithelium

Question 26

What are features of antibiotic-induced pseudomembranous colitis presentation?

Answer 26

Massive bleeding and diarrhoea

Question 27

How do you treat Antibiotic-induced pseudomembranous colitis?

Answer 27

Metronidazole / Vancomycin may need colectomy - can be fatal

Question 28

What are macroscopic features of collagenous colitis?

Answer 28

Thickened basement membrane (normal 2-3 um) | patchy

Question 29

What are microscopic features of collagenous colitis

Answer 29

Associated with intra-epithelial inflammatory cells No chronic architectural changes Loss of barrier function

Question 30

Collagenous colitis causes loss of barrier function leading to?

Answer 30

Watery diarrhea

Question 31

What is radiation colitis?

Answer 31

Chronic, inactive colitis caused by radiation therapy

Question 32

Radiation colitis may be a complication of?

Answer 32

Immunosuppression

Question 33

What are microscopic features of radiation colitis?

Answer 33

Telangiectasia

Question 34

What is telangiectasia?

Answer 34

Widened blood vessels

Question 35

What is found on histopathology for acute (infective) colitis?

Answer 35

Busy epithelium but no crypt irregularity | Focal acute cryptitis in otherwise unremarkable colonic mucosa