Which arteries supply the colon? Which part of the colon do they supply?
SMA - R and middle colic
IMA - left colic, sigmoid, sup. rectal arteries
Iliac arteries - inferior rectal
What are some infectious causes of colitis?
Bacterial - Clostridium difficle
Viral - CMV
Parasitic - Entamoeba
What is the 5 years mortality rate for toxic megacolon requiring surgery?
How do you differentiate colitis from gastroenteritis?
Colitis - bloody diarrhoea
- Older age
Gastroenteritis - Vomitting
- Young people
- Less leukocytosis
Which part of the colon is most susceptable to low flow ischaemia? Why?
Splenic flexure as it's an area of watershed
Sigmoid as inferior mesenteric is susceptable to atherosclerosis
When does CMV cause colitis?
In immunosuppressed patients
What are the anatomical types of colitis?
What are some risk factors for ischaemic colitis?
Hypercoagulable state (28% of ischaemic colitis patients)
Extreme physical activity
Why do you need to test for toxins in C. diff?
Only toxin producing strains cause colitis
(toxins A and B)
What are some causes of colitis?
What is the pathophysiology of C. diff colitis?
Disruption of normal flora by abx or chemotherapy - eg clindamycin or fluoroquinolones or penicillins
Ingestion of a toxigenic strain of C. difficle
Spores resist the gastric acid and go onto colonise the colon
How does the management of ischaemic colitis differ by location of ischaemia?
Right sided - more likely embolic - need surgery
L sided - more likely low flow - conservative
Why are abx given in ischaemic colitis?
Because bacteria can cross the wall
What is colitis?
Inflammation of the colon
Which part of the colon is more susceptable to an embolic cause of ischaemia?
Caecum as it has a end artery
When do you expect C. diff colitis?
Within 1 week of abx but up to 6 weeks after abx
How is C. diff treated?
Metronidazole (oral or IV)
2nd line: Vancomycin (oral is tolerable)
Sx if not responding to abx within hours
What do you have to rule out in entamoebic colitis?
What is toxic megacolon?
Severe inflammation causing dysfunction of muscles > severe distension of the colon > can progress to perforation
Which patients typically get ischaemic colitis?
Post open AAA repair
Post-CABs (due to bypass and low flow)
How does colitis present?
Diarrhoea +/- blood