Gastrointestinal Diseases - IBS

Question 1

What is the definition of IBS?

• symptoms
• pathogenesis
• prevalence
• subtypes of IBS

Answer 1

Irritable bowel syndrome is a chronic and relapsing gastrointestinal disorder.

Considered to be a disorder of the gut-brain axis.

Not one specific disease process, rather a collection of GI symptoms.

Symptoms:
ABC:
- abdominal pain
- bloating
- change in bowel habit (diarrhoea, constipation, frequency, consistency)

Pathogenesis:
Multi-factorial
- Altered gastrointestinal motility
- Increased gastrointestinal fermentation
- Abnormal gas transit
- Visceral hypersensitivity

Prevalence:
- UK: 6-11% population suffer
- women > men (do men suffer in silence?)
- Becoming more prevalent in elderly populations.

Subtypes:
IBS-D, IBS-C, IBS-M, IBS-U

Question 2

How is IBS assessed and diagnosed?

Answer 2

• No single diagnostic test
• ROME IV (2016)
• ‘Symptom profile’ used during assessment to track frequency & severity of symptoms

Once IBS symptoms established, tests can rule out other cause of symptoms e.g.,:
- full blood count (FBC)
- c reactive protein (CRP)
- antibody testing for coeliac

Red flags:
Unintentional and unexplained weight loss
Rectal bleeding
Family history of bowel or ovarian cancer
Change in bowel habit to looser and/or more frequent stools persisting for more than 6 weeks in a person aged over 60 years Anaemia,
Abdominal/ rectal masses, Inflammatory markers for IBD, Coeliac’s disease,
Food intolerance – Milk, specific carbohydrates.

Question 3

What are the methods of dietary assessment of IBS?

Answer 3

• Detailed food diary/diet history
• Start food/symptom diary
• Discussing any previous dietary modifications

Question 4

What is the general dietary advice for IBS?

Answer 4

(NICE 2008)
- Have regular meals (avoid missing meals & long gaps between eating)
- Eat slowly
- Reduce intake of caffeine, fizzy drinks, alcohol
- Reduce resistant starch
- Reduce F&V intake to 3x portions per day

If symptoms persist it would be appropriate to try:
- single food avoidance
- exclusion diet

Question 5

Describe the recommendations for fibre in IBS

Answer 5

Altering dietary fibre (usually lowering) is the mainstay of dietary management of IBS.
- increasing fibre intake in this group of patients would be inappropriate since it could worsen symptoms.

REDUCE:
- Short-chain soluble and highly fermentable dietary fibre, such as oligosaccharides.
- Result in rapid gas production that can cause abdominal pain/discomfort, abdominal bloating/distension and flatulence in patients with IBS.

INCREASE:
- Long-chain, intermediate viscous, soluble, and moderately fermentable dietary fiber (e.g., psyllium).
- Can improve the overall symptoms of patients with IBS.
- Supplementation with this type of dietary fibre should be recommended to patients with all of the IBS subtypes.

IBS-C
- Linseeds evidenced to ease symptoms

Question 6

Describe the low FODMAP diet in the management of IBS.

What are the benefits and limitations of low FODMAP diet?

Answer 6

Some types of carbohydrates contribute to IBS type symptoms (FODMAPs).

Fermentable:
Do not fully digest/absorb so ferment in large bowel e.g., apples

Oligosaccharides:
- Fructans (wheat, veg, onions)
- Galacto-oligosaccharides (pulses, beans, legumes)

Disaccharides:
Lactose – milk/yoghurt

Monosaccharides:
Fructose is poorly absorbed by some people

And
Polyols: Sorbitol, mannitol and xylitol (natural in fruit but also artificial sweeteners)

BENEFITS:
- All studies on low FODMAP diet have consistently shown symptomatic benefits in the majority of patients with IBS.

• Up to 86% of patients with IBS find improvement in overall gastrointestinal symptoms as well as individual symptoms
• Many people with IBS are able to reintroduce FODMAPs and control symptoms (avoids unnecessary food restrictions and helps to ensure that the patient consumes a nutritious, varied diet).

LIMITATIONS:
- Adherence by the patients and clear dietary intervention led by dietitians is vital for success.

• Risks of inadequate nutrient intake and potential adverse effects from altered gut microbiota.

Question 7

Describe the role of pre/pro/synbiotics in the management of IBS

Answer 7

Mixed evidence

• safe but ?effective
• some research shows probiotics can provide symptom relief.

Recommended to take for minimum 3/4 weeks to see benefit.

Question 8

What are the some treatments alongside dietary management for IBS?

Answer 8

Psychological
- Relaxation therapy
- CBT
- Hypnotherapy

Pharmacological
- Antispasmodics
- Fibre (fybogel)
- Laxatives
- Anti-diarrhoeal
- Antidepressants/anti-anxiety