IBS

Question 1

Define IBS

Answer 1

Chronic condition associated with bowel dysfunction and abdominal pain, otherwise unexplained

Question 2

Epidemiology

Answer 2

Female>male
10-20% of adults
Starts when young adults

Question 3

Aetiology

Answer 3

Multifactorial 
Reduced diversity of the microbiota
History of physical or sexual abuse 
FH
Previous enteric infection 
Stress
under 50

Question 4

Symptoms

Answer 4

Mild-severe lower abdo pain
Change in stool habits - can alternate between diarrhoea and constipation, and classification is based on the ratio
Abdo feels bloated
Distended abdo

Typically no nausea

Uncommon:
Urgency of defecation - typically more in Asian patients
Mucus in stool

Question 5

What is the key thing about the stool changes in patients with IBS?

Answer 5

Their abdo pain is relieved with defecation

Question 6

Signs

Answer 6

No significant signs

There may be mild tenderness in right or left lower quadrant

Question 7

Investigations

Answer 7

Bloods:
Normal FBC
IgA antitissue antiglutaminase to rule out coeliac disease
CRP (differential between IBD and IBS)

Stool:
Faecal occult blood test - typically normal
Foecal calprotectin or lactoferrin
Stool test for infections

Ultrasound
Colonscopy

Urease/hydrogen breath test

Other:
SeHCAT

Question 8

What would anaemia or raised FBC suggest?

Answer 8

That it is not IBS

Question 9

What would a positive faecal occult test suggest?

Answer 9

IBD or colorectal cancer

Question 10

When would you order a coeliac serology?

Answer 10

If there is diarrhoea and or weight loss

Question 11

What do you do if there is a positive IgA for coeliac?

Answer 11

Confirm with duodenal biopsy

Question 12

What is calprotectin and what is the foecal calprotectin test done for?

Answer 12

Calprotectin - a calcium and zinc binding protein present normally in neutrophils, released during inflammation and excreted via the stool

To differentiate between IBS and IBD

Question 13

Explain the results of a faecal calprotectin test

Answer 13

Less than 50 micrograms/g means IBS more likely (as less inflammation suggested)

Question 14

What infective organism are you specifically trying to rule out from a stool test?

Answer 14

Giardia lamblia

Question 15

What is lactoferrin and what is the result in IBS?

Answer 15

elevated in IBD?

Lactoferrin - an iron-binding protein inside neutrophils, released during infection or inflammation

Question 16

What is a SeHCAT test and what is it done for?

Answer 16

Radioactively labelled synthetic bile is given and the level of absorption is measured over a 1 week period

Question 17

What is the SeHCAT test done for?

Answer 17

This test is done in patients with chronic diarrhoea; to rule out ‘bile acid malabsorption’ which presents very similarly to IBS