Irritable Bowel Syndrome (IBS)

A functional gastrointestinal disorder characterised by chronic abdominal pain and altered bowel habits in the absence of any organic cause.

• Exact cause is unknown.
• Possible factors: Altered gut motility, visceral hypersensitivity, post-infectious changes, imbalance in gut microbiota, food intolerances, and psychological factors

• Based on predominant bowel symptom:
  • IBS-C: Constipation predominant
  • IBS-D: Diarrhoea predominant
  • IBS-M: Mixed bowel habits

• Abdominal pain or discomfort, often relieved by defecation.
• Bloating and abdominal distension.
• Altered bowel habits (constipation, diarrhoea, or alternating).
• Nocturnal diarrhoea, blood in stools, and weight loss are NOT typical of IBS and should prompt further investigation.

• Recurrent abdominal pain, on average, at least 1 day/week in the last 3 months, associated with two or more of the following criteria:
  • Related to defecation.
  • Change in frequency of stool.
  • Change in form (appearance) of stool.
• Symptoms must be present for the last 3 months with symptom onset at least 6 months before diagnosis.

• Mostly a clinical diagnosis.
• Basic tests: Full blood count, coeliac serology, CRP/ESR to exclude other conditions.
• Colonoscopy: If there are any red flag symptoms (e.g. weight loss, rectal bleeding).

• Dietary and lifestyle: Regular meals, reduced caffeine/alcohol, low FODMAP diet.
• Pharmacological: Laxatives(for IBS-C), antispasmodics(e.g. mebeverine), and antidiarrhoeals (e.g. loperamide for IBS-D).
• Psychological therapies: Cognitive behavioural therapy, hypnotherapy, and psychotherapy have shown benefit in some patients.

• IBS is a chronic condition, but it does not increase the risk for more serious conditions like colon cancer.
• Many people can manage symptoms with lifestyle changes, diet, and medications.