Irritable Bowel Syndrome/intolerance

Question 1

IBS/intolerance:

Mechanism for symptoms?

Answer 1

Increased sensitivity and/or lower visceral nociceptive threshold to luminal distension.

Question 2

IBS/intolerance:

Is it a diagnosis of exclusion?

Answer 2

No. It is a clinical diagnosis in the abscence of red flags.

Question 3

IBS/intolerance:

Predominant IBS types?

Answer 3

Diarrhoeal
Constipation
Mixed

Question 4

IBS/intolerance:

Differential diagnosis to consider or comorbid mechanisms for symtpoms?

Answer 4

• Food intolerances
• pain hypersensitivity
• Anxiety/Stress influenced (psychosomatic)
• Altered gut microbiome
• altered serotonin metabolism
• low grade GIT inflammation

Question 5

IBS/intolerance:

Diagnostic criteria?

Answer 5

Diagnosis:
1) No red flags
· It is a clinical diagnosis in the absence of red flags:
-<6 months symptoms
-Rectal bleeding
-Weight loss
-Unexplained fever
-Nocturnal symptoms
-FHx of IBD, coeliac or CRC
-Faecal incontinence
-Extraintestinal manifestations
-Abdominal mass

2) Rome IV criteria met
symptoms for ≥ 6 months and the following met in the previous 3 months
a) Recurrent abdominal pain ≥ 1 days/week
AND
b) ≥2 of the following:
-abdominal pain related to defecation
-change in frequency of bowel motions
-change in form of stools

Question 6

IBS/intolerance:

Tests worth considering?

Answer 6

CBE, CRP, ESR, iron studies, coeliac serology, EUC/LFT, stool MCS and C.difficile toxin, faecal calprotectin

Question 7

IBS/intolerance:

Should coeliac genteic screening be tested?

Answer 7

No. More than 30% of IBS patients share the HLA DQ2/8 gene with coeliac disease patients

Question 8

IBS/intolerance:

Intolerances to think of in IBS patient?

Answer 8

• Lactose (dairy - highest concentration in soft or liquid forms)
• Fructose (mangoes, pears, dates, stone fruit, berries, dried fruit, honey)
• Sorbitol (apples, pears, cherries, apricots, prunes, plums)
• Fructans (onions, leeks, asparagus, wheat, barley, oats)
• Fats

Question 9

IBS/intolerance:

How much milk can lactose intolerant patients require before symtpoms?

Answer 9

typically less than 200mL of milk is tolerated

Question 10

IBS/intolerance:

If someone is having symptoms after a tea or coffee with milk are they lactose intolerant?

Answer 10

Unlikely if the milk volume is less than 200mL. it is more likely an issue with the fat component or the caffeine

Question 11

IBS/intolerance:

If fats are not as well tolerated in dairy what foods will be difficult to tolerate?

Answer 11

The more solid the dairy product typically the higher the fat content. Hence icecream will less tolerated than milk.

Question 12

IBS/intolerance:

Why are fats an issues?

Answer 12

• increase the gastrocolic reflex (increased motility/distension when activated)
• increases colonic hypersensitivity
• changes motility and visceral sensations

Question 13

IBS/intolerance:

How does fructose and sorbitol impact IBS patients?

Answer 13

This combination tends to have a significant impact on IBS patients even at low doses.

Question 14

IBS/intolerance:

How to test intolerances the sugars?

Answer 14

Hydrogen breath test.

The fermented sugar if malabsorbed is reabsorbed in the colonic circulation and lost in exhaled air.

Question 15

IBS/intolerance:

What does a positive hydrogen breath test mean for the patient?

Answer 15

Typically it means restriction of the offending sugar NOT elimination because there wil be a tolerance threshold prior to developing malabsorption.

Question 16

IBS/intolerance:

IBS management?

Answer 16

Management:
1) Empathy (some studies find symptoms improve by as much as 20%) and provide a clear diagnosis

Patients who had meaningful relationships with doctors has less symptoms, better adherance to treatment and greater satisfaction

2) Dietary adjustments
the most common feedback from consumers is a lack o time spent on the dietary information

· Diarrhoeal type:
-smaller frequent meals
-avoid alcohol and caffeine
-6 week dietitian guided low FODMP diet then followed by gradual reintroduction of foods (not to be long-term as associated with abnormal GIT microbiome) – improvement of severity, symptoms and QOL by ≤80%
- Fructose and sorbitol combination tends to have a significant impact on IBS patients even at low dose

· Constipation type:

• increase insoluble fibre
• Low dose Polyethylene Glycol (PEG)
• Intermittent stimulant laxative eg. Senna
• Prucalopride (5HT4 angonist - increases motility, headache as side effect, expensive)
• Enemas
• Anorectal/pelvic floor biofeedback and pelvic floor physiotherapy

3) Lifestyle adjustments
· Improve sleep
· Improve physical activity
· Smoking cessation

4) minor role for:
· hyoscine
· peppermint oil
· Iberogast

5) TCA (diarrhoeal type) as they can constipate and improve overall symptoms
6) SSRIs (constipation type) as they can cause diarrhoea
7) CBT (best for stress related type of IBS) (need a functional bowel specialist psychologist)
8) Gut focussed hypnotherapy (as effective as a low FODMAP diet – 70-80% over 6 – 12 sessions)