Bristol Stool Chart
| Type | Description | What It Means |
|---|---|---|
| Type 1 | Separate hard lumps (like nuts) | Severe constipation — needs treatment |
| Type 2 | Sausage-shaped but lumpy | Mild constipation |
| Type 3 | Like a sausage with cracks | Borderline normal |
| Type 4 | Like a smooth sausage or snake | Ideal — normal |
| Type 5 | Soft blobs with clear-cut edges | Bordering on diarrhoea |
| Type 6 | Fluffy pieces with ragged edges | Mild diarrhoea |
| Type 7 | Entirely liquid, no solid pieces | Watery diarrhoea — risk of dehydration |
The Gut Microbiome: What We Know
- A healthy gut contains 1,000+ bacterial species and 37 trillion microorganisms
- Diversity of the microbiome is the key marker of gut health — reduced diversity is associated with IBS, IBD, obesity, and depression
- Firmicutes:Bacteroidetes ratio is altered in obesity but causation is unclear
- Short-chain fatty acids (SCFAs) produced by fermentation of fibre protect the gut lining and reduce systemic inflammation
- The gut-brain axis links microbiome composition to mood, cognition, and mental health via the vagus nerve
Improving Gut Health
- Eat 30+ different plant foods per week — greatest driver of microbiome diversity
- Prioritise dietary fibre (30g/day) — prebiotic fuel for beneficial bacteria
- Include fermented foods: live yoghurt, kefir, kimchi, sauerkraut, miso — evidence for direct microbiome benefit
- Limit ultra-processed foods — associated with reduced microbiome diversity
- Reduce unnecessary antibiotics — each course reduces microbiome diversity for weeks to months
- Regular exercise — independently improves microbiome diversity
30 Plants Per WeekThe American Gut Project found that people eating 30+ varieties of plant foods per week had significantly more diverse microbiomes than those eating fewer than 10. Count every plant: fruits, veg, nuts, seeds, legumes, wholegrains, herbs, and spices.
Are probiotics useful?
Specific strains have evidence for specific conditions: Lactobacillus rhamnosus GG (prevention of antibiotic-associated diarrhoea); VSL#3 (pouchitis in IBD); Saccharomyces boulardii (C. diff recurrence prevention). Generic probiotic supplements have modest evidence for general gut health.
What is a normal bowel movement frequency?
Between 3 times per day and 3 times per week is considered normal range. More important than frequency: consistency (Bristol 3–4), ease of passage, and absence of pain or blood.
Do I need a colonoscopy after age 50?
The NHS offers bowel cancer screening via FIT test (home stool test) from age 50–74. A positive FIT test leads to colonoscopy. Symptomatic patients or those with family history should see their GP regardless of age.
What does mucus in stool mean?
Small amounts of mucus are normal — the colon produces it as lubrication. Significant amounts of mucus — especially with diarrhoea, blood, or abdominal pain — may indicate IBS, IBD, polyps, or infection. Warrants GP assessment.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.