GP - Irritable Bowel Syndrome (IBS)

Question 1

Patients with IBS have changes in bowel habit (diarrhoea/ constipation), so they are often classified by the predominant stool type into the following subtypes according to the Rome IV criteria. What are these subtypes?

Answer 1

Diarrhoea-predominant (IBS-D) - most common subtype

Constipation (IBS-C)

Mixed i.e. fluctauting between diarrhoea and constipation (IBS-M)

Unclassified (IBS-U)

Question 2

What are the causes for IBS?

Give 3 risk factors for IBS

Answer 2

Cause is UNKNOWN

Risk factors include genetics, gastroenteritis, IBD, diet consisting of alcohol, caffeine, spicy and fatty foods, antibiotics, stress (anxiety, depression)

Question 3

What age range does IBS usually affect?

Women or men more common?

Answer 3

20-30 yrs old

More common in women

Question 4

What clinical features does a patient with IBS have?

Answer 4

6 months of ABC:

• Abdominal pain
• Bloating
• Changes in bowel habit (diarrhoea/ constipation)

Make a diagnosis of IBS if a person has abdominal pain which is either:

• Related to defecation, and/or
• Associated with diarrhoea/ constipation, and /or
• Associated with altered stool form (hard, lumpy, loose, or watery), AND
• There are at least 2 of the following:
  
  • Altered stool passage (straining, urgency, incomplete evacuation)
  • Bloating
  • Symptoms worsened by eating
  • Passage of mucus, and
  • Alternative conditions with similar presentations have been excluded

* Remember that weight loss is NOT a sign of IBS

Question 5

What examinations would you perform as a GP?

Answer 5

• Abdominal examination - palpate the abdomen for tenderness or masses
• DRE to exclude perianal or rectal pathology
• Check BMI and assess for any unexplained weight loss

Question 6

What investigations would you do for IBS?

Answer 6

• Blood tests - FBC, U&Es, CRP, ESR, tTG-IgA
  
  • FBC to rule out anaemia and infection (e.g. gastroenteritis)
  • U&Es to assess renal function due to diarrhoea
  • CRP, ESR to see if there is active inflammation or infection
  • tTG-IgA (and endomysial antibody IgA) to rule out coeliac pathology
• Faecal calprotectin - normal in IBS but raised in IBD

Question 7

Give 3 differential diagnoses of IBS?

Answer 7

Conditions that cause diarrhoea:

IBD

Coeliac disease

Colorectal cancer

Diverticular disease

Gastroenteritis

Conditions that cause constipation:

Hypothyroidism

Question 8

What advice would you give to a patient with IBS?

Answer 8

Advice:

• Advise the person to eat a healthy, balanced diet, and avoid alcohol, caffeine, spicy and fatty foods
• Encourage the person to identify any stress, anxiety or depression and manage appropriately
• Advise adequate fluid intake
• For patients with predominant symptoms of diarrhoea, advise the person to reduce their intake of insoluble fibres e.g. wholemeal or high-fibre flour and breads
• For patients with predominant symptoms of constipation, advise the person to try soluble fibre supplements (ispaghula) or foods high in soluble fibres e.g. oats
• Advise to have regular physical activity and lose weight if overweight

Question 9

What medical management can you do for a patient with IBS?

Answer 9

• If symptoms of constipation persist –> bulk-forming laxative (Ispaghula husk)
  
  • If still doesn’t work –> linaclotide
• If symptoms of diarrhoea persist –> loperamide
• If ongoing symptoms of abdominal pain or spasm –> antispasmodic drug e.g. mebeverine hydrochloride
  
  • If abdominal pain persists –> TCA e.g. amitriptyline

Question 10

When should you refer the patient with IBS?

Answer 10

Referral to a gastroenterologist if:

Persistent symptoms despite optimal management in primary care

Uncertainty about the diagnosis

Question 11

What are the red flags of IBS?

Answer 11

Rectal bleeding

Unexplained/ unintentional weight loss

FHx of bowel or ovarian cancer

Onset after 60 yrs of age