Irritable Bowel Syndrome and Functional Dyspepsia

Question 1

What is IBS?

Answer 1

IBS = a functional bowel disorder defined as recurrent episodes (in the absence of detectable pathology)

Rome criteria
abdominal pain/discomfort 1 day/week for >3 months with 2 of the following:
•	Altered stool passage
•	Abdominal bloating
•	Symptoms made worse by eating
•	Passage of mucus

Question 2

What is the aetiology of IBS?

Answer 2

Unknown – no specific findings (Mucosal biopsies are normal)

Assumed to be disorder of altered gastrointestinal motility
Intestinal microbiota – particularly those with bloating
Actions on certain foods (particularly carbohydrates)
Effects on epithelial barrier integrity and enteroendocrine signalling

Question 3

What are the risk factors of IBS?

Answer 3

Physical/sexual abuse
Age <50yrs
Female
Previous enteric infection
Work/job stress

Question 4

What is the epidemiology of IBS?

Answer 4

Common (10-20% of adults)
Seen in adults and adolescents
2x more common in women

Question 5

What are the symptoms of IBS?

Answer 5

Abdominal pain - Often colicky, in the lower abdomen
Relieved by defacation or flatus
Over 6 months

Bloating - Increases during the day

Altered bowel frequency

Change in stool consistency - Mucus

Passage with urgency or straining
Rule out colonic malignancy with RFS

Weight loss

PR bleed

Anaemia

Late onset (>60 years old)

Question 6

What are the signs of IBS?

Answer 6

Usually normal
Distention
Mild tenderness in one/both iliac fossa

Question 7

What investigations can be done for IBS?

Answer 7

Bloods
FBC: Normal – anaemia suggests non-IBS
Anti-endomysial Abs: Normal – raised in coeliac
Anti-TTG Abs: Normal – raised in coeliac

Stool studies - Normal

Plain AXR - Normal

Endoscopy – flexible sigmoidoscopy, colonoscopy - Normal (abnormal suggests IBD)

Other investigations
Hydrogen breath test - Normal – raised in bacterial overgrowth, lactase deficiency

Faecal calprotectin - <40 mg/g

CRP - <0.5 mg/L

Question 8

How is IBS managed?

Answer 8

Lifestyle modifications
Reduce stress

Dietary modifications
Eliminate precipitating substances – FODMAP - caffeine, lactose, fructose
Addition of fibre – can cause flatulence/bloating
Probiotics
Reduce insoluble fibre

Laxatives
1st line: ispaghula, lactulose, polyethylene glycol
2nd line: SSRI

Antispasmodics
If pain/bloating – do not affect changes in bowel pattern
Peppermint oil, dicylcoverine

Anti-diarrhoeals
1st line: loperamide

Psychological therapies – e.g. CBT

Question 9

What are the possible complications of IBS?

Answer 9

Physical/psychological morbidity (damage to family/work relationships)
Colonic diverticulosis

Question 10

What is the prognosis for IBS?

Answer 10

Normal life expectancy and no complications
Chronic relapsing and remitting course
Exacerbated by psychosocial stresses