Irritable Bowel Syndrome

Lifestyle modifications


  • More than 25% of people with IBS may improve on placebo (1)
  • In 80% of patients certain types of foods may aggravate the symptoms. Reduce or avoid factors that make the symptoms worse. It may include caffeine, fructose and lactose (1)
  • Low FODMAP diet: This diet is low in poorly absorbed short-chain carbohydrates (1). The diet may reduce diarrhoea, pain, bloating and flatus (1). 4-6 weeks on a low FODMAP diet is enough to consider if a person will respond positively on this diet (1). Three phases:
    • A) Reduced FODMAP for 4-6 weeks
    • B) Reintroduction of FODMAP foods
    • C) personalization of diet based on effects of reintroduction (1)
  • Probiotic: May benefit some patients with IBS. If a probiotic is tested it is recommended to use it in the dose that the manufacturer recommends for 12 weeks to evaluate the effect (1).
  • Soluble fiber (eg. beans, oat bran, barley, isphagula) may help with predominantly IBS with constipation, or IBS with alternating constipation and diarrhoea. Fiber dose: Begin with 3-4g/day and gradually increase to avoid bloating (1)
  • Insoluble fiber should be avoided by people with IBS (1)


  • Regular physical activity may reduce some of the symptoms, including constipation (1)


  • Lifestyle changes that reduce stress is recommended (1)





Figure: Evidence pyramid

Evidence based on guidelines and evidence based Clinical Decision Systems is written in BOLD font

Evidence based on meta analysis or systematic reviews is written in BOLD and CURSIVE font

​Evidence based on randomized controlled trials is written in PLAIN font

Evidence based on observational / cohort studies is written in CURSIVE font