Infectious colitis (GI)

Question 1

Define infectious colitis.

Answer 1

Inflammation of the colon due to bacteria, parasites or viruses - common condition

Question 2

How does infectious colitis differ from ulcerative colitis?

Answer 2

UC is not due to infection

Question 3

What are the risk factors for infectious colitis? (4)

Answer 3

• lack of sanitation
• drinking contaminated water
• antibiotic use
• hospitalisation or nursing home

Question 4

What bacteria commonly causes infectious colitis?

Answer 4

C. diff - gram +ve rod that causes pseudomembranous colitis (inflammation of colon and formation of pseudomembranes)

Question 5

What are some risk factors for C. diff infection - infectious colitis? (2+4)

Answer 5

• antibiotics - 4Cs:
  
  • clindamycin
  • clarithromycin
  • ciprofloxacin
  • cephalosporins (cefotaxime, ceftriaxone)
• PPIs

Question 6

What problems does C. diff infection (infectious colitis) cause in the GI system?

Answer 6

Perforation or toxic megacolon

Question 7

What is toxic megacolon (infectious colitis)?

Answer 7

Toxic colitis with an associated megacolon (colonic distension >6cm) - potentially lethal complication of acute colitis, and is defined as total or segmental non-obstructive colonic distension associated with systemic toxicity

Question 8

What investigations may be useful to detect toxic megacolon/perforation as a result of C. diff infectious colitis?

Answer 8

AXR and CT

Question 9

What may we see on colonoscopy in C. diff infectious colitis (pseudomembranous colitis)?

Answer 9

Yellow plaques on intraluminal wall of colon

Question 10

What are the clinical features of infectious colitis? (7)

Answer 10

• diarrhoea - may be watery or blood-stained
• blood and mucus in stool
• lower abdominal pain and tenderness
• fever and malaise
• nausea and vomiting (may be absent)
• abdominal distension (may be absent)
• symptoms of shock (suggests fulminant colitis)

Question 11

What investigations do we do for C. diff infectious colitis (pseudomembranous colitis)? (3)

Answer 11

• stool culture/PCR - C. diff toxin can be identified
• FBC - raised WCC
• AXR - severe colitis can cause toxic megacolon = lethal

Question 12

Why do we not use C. diff antigen positivity for pseudomembranous colitis?

Answer 12

It only shows exposure to the bacteria rather than current infection

Question 13

How can we visualise the colonic inflammation in infectious colitis?

Answer 13

Colonoscopy

Pseudomembranous colitis (C. diff) –> yellow plaques on intraluminal wall of colon

Question 14

What do we need to always ask patients with suspected infectious colitis about?

Answer 14

Previous travel history

Question 15

What are the criteria for diagnosing toxic megacolon (infectious colitis complication)?

Answer 15

Radiographical evidence of acute colitis and 3/4 following features:

• fever >38.6C
• heart rate >120bpm
• WCC >10.5x10^9/L
• anaemia

One of the following is also required: volume depletion, mental status changes, electrolyte abnormalities or hypotension

Question 16

What conservative treatment do we give for infectious colitis?

Answer 16

Hydration to replace lost fluids

Question 17

How do we manage the diarrhoea in infectious colitis?

Answer 17

Loperamide (anti-diarrhoeal)

Question 18

How do we manage the infectious agent in infectious colitis?

Answer 18

Abx specific to the agent

Question 19

How do we manage C. diff infectious colitis (pseudomembranous colitis)?

Answer 19

• oral vancomycin or fidaxomicin
  
  • 1. oral vancomycin for 10d
  • 2. if no response/recurrent episode within 12wk –> oral fidaxomicin
  • if no response OR life-threatening –> oral vancomycin + IV metronidazole (–> tigecycline or IVIg)
• discontinue causative agent (4Cs)
• supportive care
• infection control measures

Question 20

What could we consider in those with severe/refractory C. diff infectious colitis?

Answer 20

Faecal microbiota transplant

Question 21

What medication do we hold in C. diff patients?

Answer 21

Opioids

Question 22

What is an important complication of infectious colitis?

Answer 22

Toxic megacolon

Question 23

How do we manage toxic megacolon (infectious colitis)?

Answer 23

• resuscitation and monitoring + Abx
• if no improvement with medical management after 72h/complications (perforation, haemorrhage, worsening) –> surgery (abdominal colectomy with end-ileostomy)