Irritable Bowel Syndrome

Question 1

What is Irritable Bowel Syndrome

Answer 1

IBS is a syndrome of abdominal symptoms for which no organic cause can be found. It is thought to be due to an abnormal brain-gut axis

Question 2

What will you find in a history of Irritable Bowel Syndrome

Answer 2

Symptoms:
Diagnostic criteria:
Recurrent abdominal pain S (Commonly LLQ) T(Early morning rush) A(Worse on eating) R(Defecation), for at least 1 day of each week, lasting more than 3 months, associated with 2 of:
Relief on defecation
Altered stool form - Constipation and diarrhoea (Can be either and may alternate)
Altered bowel frequency – Increased or decreased frequency, can alternate. Associated with urgency, tenesmus

Other Symptoms not diagnostic - Abdominal bloating/distension, Mucous in stool, Symptoms worsen with stress, gastroenteritis or menstruation, “Early morning rush”

Risk Factors:
Female

Specific Questions to ask:
Features that make IBS less likely and require referral - Weight Loss, Nocturnal Symptoms, Rectal Bleeding, Worsening symptoms, Fever, Steatorrhea, Age > 60, Family history of bowel or ovarian cancer, Anaemia, raised inflammatory markers
Assess for risk factors – Stress, Onset after a gastroenteritis

Differentials:
Colorectal cancer – Weight loss, constitutional symptoms
Crohns or UC – Systemic response with raised inflammatory markers
Coeliac Disease – May president similarly, exclude with anti-tissue transglutaminase
Gastroenteritis – Inflammatory response, exclude with stool cultures if signs like fever etc
Diverticular Disease
Thyroid Abnormalities – May have other symptoms of thyroid problems, exclude with bloods
Anxiety – May precipitate IBS
Ovarian Cancer/PID – Abdominal discomfort and bloating, may have urinary or vaginal symptoms, rule out with Ca-125

Question 3

What will you find on examination of IBS?

Answer 3

Examination: Most commonly a completely normal examination

Possible mild tenderness in lower quadrants (commonly LLQ)

Question 4

What investigations will you order in suspected Irritable Bowel Syndrome

Answer 4

Investigations: There is no diagnostic test for IBS, so investigations are used to rule out differentials.
Bedside:
Stool cultures (send multiple samples)– Only if infection suspected, to rule out infective causes.
Test any stool sent for C. Diff

Bloods:
FBC – to assess any raised WBC (indicating infection) or for any anaemias (suggesting blood loss/malabsorption)
CRP/ESR - Should be normal, if raised think something else
Coeliac Screen - To rule out coeliac
Ca-125 – to rule out ovarian cancer
TSH - If other features of hyper/hypothyroidism

Imaging:
Colonoscopy – Only If red flags present

Special Tests:
Faecal calprotectin – to rule out IBD
Faecal Occult blood – If cancer suspected
Can try lactose free diet for 1 week with lactase supplement, to see if the patient is lactose intolerant

Question 5

What is the treatment of irritable Bowel Syndrome

Answer 5

Lifestyle:
Regular meals
Lots of fluid
Reduced alcohol and fizzy drinks
Ensure a heathy diet
Adjust fibre foods – more in constipation, less in diarrhoea
If diet plays key role in symptoms, consider dietician referral
Consider CBT as can have big psychological impact

Medical: There is no cure, so medication is used for symptom management
Constipation - Consider ispaghula (laxative) after attempting dietary changes
Diarrhoea - Consider loperamide (anti diarrhoeal) after attempting dietary changes
Bloating - Mebeverine (Antispasmodic)
Patients may require antidepressants if it is having a big effect on their life