IBS Guidance
Medical disclaimer
This resource is for educational and informational purposes only.
The content on this page — including dietary guidelines, supplement recommendations, and symptom management strategies — does not constitute medical advice, diagnosis, or treatment.
It is intended to support qualified nutrition and health coaching professionals as a general reference tool, and should not be used as a substitute for personalised advice from a registered dietitian, gastroenterologist, or other licensed healthcare provider.
If you or your client are experiencing symptoms that may be consistent with Irritable Bowel Syndrome (IBS) or any other gastrointestinal condition, always seek a formal medical diagnosis before implementing any dietary intervention.
Red flag symptoms (listed below) require immediate referral to a GP or clinician.
Individual responses to dietary changes vary — what works for one person may not work for another.
Coaches should operate strictly within their scope of practice at all times. (NICE, 2015)
IBS symptom quick-action guide
Select a symptom below — see immediate steps, things to consider, and what to avoid
Second-line intervention
Low FODMAP diet guide
Only introduce when general dietary advice has been unsuccessful. Always deliver with professional supervision. (NICE, 2015; Staudacher et al., 2011)
Note: Bowel habit subtypes should be classified only on days with abnormal bowel movements. Portion size matters — some high-FODMAP foods may be tolerated in small amounts. Use a validated FODMAP app (e.g. Monash University) to check serving sizes. (Nanayakkara et al., 2016; Halmos et al., 2014)
Portion size matters even for low-FODMAP foods. Some foods become high-FODMAP in large quantities. Always use the Monash University FODMAP app as the gold-standard reference for current, validated portion sizes. (Adapted from Nanayakkara et al., 2016)
How to run the low FODMAP protocol
The 3-phase process
Elimination phase
Strictly eliminate all high-FODMAP foods for 4–8 weeks. Monitor symptom response using a food and symptom diary. Do not extend beyond 8 weeks.
- Assess baseline symptoms first
- Check for nutritional adequacy
- Ensure adequate protein and fibre
Reintroduction phase
Systematically reintroduce one FODMAP category at a time over 8–10 weeks. Test each group with 3-day washout periods between challenges.
- Reintroduce one FODMAP type at a time
- Start with small portions
- Track symptoms for 3 days per food
Personalisation phase
Build a sustainable, personalised long-term diet that includes all tolerated foods and avoids only confirmed trigger FODMAPs.
- Reintroduce tolerated foods freely
- Aim for maximum dietary variety
- Reassess triggers periodically
These symptoms are not consistent with IBS alone. Rule out IBD, Coeliac Disease and colorectal cancer before any dietary intervention begins. (NICE, 2015)
Educational resource only — not medical advice. This page has been compiled from peer-reviewed research and evidence-based clinical guidelines for use by qualified nutrition and health coaching professionals. It does not replace a formal medical assessment or the advice of a registered dietitian or gastroenterologist. All dietary interventions should be tailored to the individual by a suitably qualified practitioner. Citations included throughout are for reference only. © getfitwithnadir.com