Irritable bowel syndrome

Question 1

What is irritable bowel syndrome?

Answer 1

Group of abdominal symptoms for which no organic cause can be found.
Probably due to disorders of intestinal motility.

Question 2

Epidemiology of IBS

Answer 2

More common in females

Age at onset is under 40

Question 3

Clinical presentation of IBS

Answer 3

Subtypes depending on predominant stool pattern
IBS with constipation
IBS with diarrhoea
Mixed IBS

Only diagnose IBS if abdominal pain is relieved by defecation OR associated with altered stool form or bowel frequency 
AND 2 symptoms from: 
Urgency
Incomplete evacuation 
Abdo bloating/distention
Mucous or purulent discharge
Worsening of symptoms after food

Examination may be normal or show: abode tenderness

Question 4

Non GI symptoms?

Answer 4

Nausea, bladder problems, back pain

Question 5

Diagnostic tests and results for IBS

Answer 5

FBC, CRP, ESR, U&E
Faecal calprotectin- marker of bowel inflammation, raised in IBD
Serum CA-125 (tumour cell protein marker) to exclude ovarian cancer.
Coeliac screen.
Colonoscopy if over 50 or any sign of organic disease.

Question 6

Dietary advice for IBS

Answer 6

Fibre, lactose, fructose, wheat, starch, caffeine, sorbitol, alcohol and fizzy drinks may worsen symptoms.

Question 7

Treatment for IBS with constipation

Answer 7

Increased fibre will worsen flatulence and bloating.

Bisacodyl and sodium picosulfate (laxatives that encourage peristalsis)

Ispaghula has non-fermentable water-soluble fibre, absorbs water into faeces.

Question 8

Treatment for IBS with diarrhoea

Answer 8

avoid sorbitol sweetners (corn syrup)

Bulking agent ± loperamide after each loose stool

Question 9

How does loperamide work?

Answer 9

Opioid that doesn’t penetrate CNS, acts as agonist of opioid receptors in GI tract
decreases activity of myenteric plexus- slows peristalsis

Question 10

Treatment for colic/ bloating

Answer 10

Oral antispasmodics (prevent muscle spasm)– 
e.g. mebervine,