Severe Acute Diarrhoea

Question 1

What defines severe acute diarrhoea?

Answer 1

Increased frequency.
Increased volume.
Decreased consistency.
(Urgency is different and suggests rectal pathology e.g. UC, cancer).

Question 2

What are the differential diagnoses for severe acute diarrhoea?

Answer 2

Gastroenteritis (suspected if <2wks).
IBD.
IBS.
Coeliac disease.
Thyrotoxicosis.
Colorectal cancer.
Drugs.

Question 3

What presentation suggests that severe acute diarrhoea is associated with gastroenteritis? What other questions should you ask?

Answer 3

May be vomiting alongside.
Check travel history, change in diet, contact history, blood? (may suggest campylobacter, shigella, salmonella, E.Coli).
Could be due to C.DIFF causing PSEUDOMEMBRANOUS COLITIS (more likely if recent hospital admission or abx use).

Question 4

What presentation suggests that severe acute diarrhoea is associated with IBD?

Answer 4

UC often bloody.

Crohn’s may also cause B12 or iron deficiency anaemia.

Question 5

What presentation suggests that severe acute diarrhoea is associated with IBS?

Answer 5

Longstanding history of non-specific diarrhoea and constipation, worse with stress.
If anorexia, weight loss, nocturnal diarrhoea or anaemia, suggests an organic cause instead.

Question 6

What presentation suggests that severe acute diarrhoea is associated with coeliac disease?

Answer 6

Will likely also be iron deficiency anaemic, bloating, coeliac serology positive.

Question 7

What presentation suggests that severe acute diarrhoea is associated with thyrotoxicosis?

Answer 7

Will likely have other symptoms too such as weight loss, heat intolerance, tachycardia, palpitations, insomnia.

Question 8

What presentation suggests that severe acute diarrhoea is associated with colorectal cancer?

Answer 8

Often have systemic symptoms such as weight loss or appetite loss.

Question 9

What drugs can cause severe acute diarrhoea?

Answer 9

Alcohol, digoxin, NSAIDs, propanolol, cimetidine, PPIs, abx.

Question 10

What investigations should be performed for a presentation of severe acute diarrhoea?

Answer 10

Bloods:
- FBC - look for iron deficiency anaemia.
- U&Es
- CRP - inflammation in IBD or cancer.
- TFTs
- Coeliac serology
Blood and stool cultures.
PR exam.
Flexi sig.

Question 11

How is severe acute diarrhoea managed?

Answer 11

Treat cause.
Oral rehydration (better than IV if poss).
Codeine or loperamide.
Avoid abx unless bacterial cause.

Question 12

What is the aetiology of pseudomembranous colitis?

Answer 12

Disruption of gut ecology in abx use. Caused by C.DIFF.

Question 13

What are the signs of pseudomembranous colitis?

Answer 13

Temperature, colic, diarrhoea (with smell).

Question 14

What would lab tests show if pseudomembranous colitis were present?

Answer 14

Raised CRP, WCC.

Decreased albumin.

Question 15

What is the management of pseudomembranous colitis?

Answer 15

Stop causative antibiotics and start METRONIDAZOLE or vancomycin if severe.

Question 16

What are the possible complications of pseudomembranous colitis?

Answer 16

Toxic megacolon and multi-organ failure.