IBS is one of the most common conditions a UK GP sees, and one of the most frustrating to live with. Symptoms are real and often disabling, but there's no single test that diagnoses it and no single treatment that fixes it. This article walks through how clinicians approach it, what genuinely helps, and where the red flags are.

What IBS is and how it's diagnosed

IBS is a disorder of gut-brain interaction characterised by recurrent abdominal pain or discomfort related to bowel habit, with no structural cause found on investigation. The diagnostic framework UK clinicians use (the Rome criteria) requires symptoms for at least 6 months with specific features — pain related to defaecation, change in stool frequency, change in stool form.

Subtypes matter for treatment: IBS-D (diarrhoea-predominant), IBS-C (constipation-predominant), and IBS-M (mixed). The same condition presents very differently between people.

Common triggers

Triggers vary widely, but the most commonly identified are:

  • Specific foods — particularly fermentable carbohydrates (FODMAPs), caffeine, alcohol, fatty meals, spicy foods.
  • Stress and anxiety — gut-brain signalling is bidirectional, and stress reliably flares IBS for many people.
  • Sleep disturbance — poor sleep worsens both visceral sensitivity and motility.
  • Hormonal cycles — many women notice flares around their period.
  • Antibiotics or gastroenteritis — post-infectious IBS is a recognised pattern.

First-line: dietary approaches

NICE recommends starting with general dietary advice — regular meals, adequate fluid, limited alcohol and caffeine, reduced fatty/spicy food. For patients whose symptoms don't respond, a structured low-FODMAP approach is the most evidence-based next step.

Low-FODMAP isn't a long-term diet. It's three phases: a strict 4–6 week restriction, then systematic reintroduction to identify specific triggers, then a personalised long-term diet that keeps only the relevant restrictions. Done properly — ideally with a dietitian — it works for around two-thirds of IBS patients.

Pharmacological options

UK clinicians have several targeted options:

  • Antispasmodics like mebeverine or alverine for cramping.
  • Loperamide for diarrhoea-predominant symptoms.
  • Laxatives (usually polyethylene glycol or other osmotic laxatives) for constipation-predominant symptoms.
  • Peppermint oil capsules — better evidence than people expect for cramping and bloating.
  • Low-dose tricyclics or SSRIs for refractory cases — used at lower doses than for depression, targeting gut-brain pathways.
  • Rifaximin for selected diarrhoea-predominant cases.

Stress, sleep and gut-directed approaches

Cognitive behavioural therapy adapted for IBS (CBT for IBS) and gut-directed hypnotherapy both have NICE-supported evidence for moderate-to-severe IBS that hasn't responded to other measures. They aren't placebos — the gut-brain axis is biological, and these interventions target it.

When to investigate further

The classic IBS red flags warrant separate investigation:

  • Unintentional weight loss
  • Blood in stool
  • Anaemia on blood tests
  • New change in bowel habit aged over 50
  • Family history of bowel or ovarian cancer
  • Persistent symptoms despite first-line treatment

These aren't IBS unless other causes — coeliac disease, inflammatory bowel disease, malignancy — have been ruled out.

Working with your Farmeci clinician

A consultation typically covers your symptom pattern, what triggers you've identified, what dietary changes you've tried, and any red-flag symptoms. From there, your clinician can recommend the right next step — dietitian referral, antispasmodics, targeted treatment for your subtype, or investigation if anything looks atypical.