Irritable Bowel Syndrome

 

• Definition and presentation

  Abdominal pain >6 months which is:

  • Relieved by defecation.
  • OR associated with altered bowel habits and ≥2 of TEnse BUM: Tenesmus, Exacerbated by Eating, Bloating, faecal Urgency, Mucus PR.

  Other features:

  • Symptoms may be exacerbated by stress.
  • General abdominal tenderness.
  • Can lead to feelings of anxiety and depression.

  Red flag symptoms suggesting it is not IBS:

  • PR bleeding.
  • Nocturnal symptoms.
  • Weight loss
  • Family history of bowel or ovarian cancer.
  • Change in bowel habit >6 weeks in someone >55 years old.

• Risk factors

  • Female
  • Age 20-40.

• Investigations

  Rule out other causes:

  • Examination: abdominal or rectal masses.
  • FBC, ESR/CRP, and coeliac antibodies are reasonable initial tests. Faecal calprotectin if still not sure if IBS or IBD.
  • Further tests – imaging, TFTs, hydrogen breath test, and FOB – are not indicated in those who meet the IBS criteria.
  • Check CA-125 if ovarian cancer suspected.

• Management

  Lifestyle and dietary advice:

  • Regular meals, good hydration (8 cups per day).
  • Reduce alcohol, max 3 cups tea/coffee per day, max 3 fruit portions per day.
  • Dietary fibre: avoid too much fibre, especially insoluble (e.g. bran), but encourage soluble fibre (e.g. ispaghula powder) if constipated.
  • Encourage exercise.
  • Low FODMAP diet (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) if symptoms persist.

  GI drug options:

  • Mebeverine, an antimuscarinic antispasmodic that reduces bloating.
  • Loperamide for diarrhoea.
  • Laxatives: ispaghula husk, senna, or docusate. Linaclotide if other agents don't work.
  • Metoclopramide, which has prokinetic and antiemetic effects, can reduce dyspepsia.

  Psychiatric:

  • CBT if no response to drug therapy after 1 year.
  • TCA if laxatives, loperamide, and antispasmodics haven't worked. SSRIs 2nd line.