Calculators & Tools

Bristol Stool Form Scale

Classifies stool form - used to characterise constipation and diarrhoea.

1 What is the Bristol Stool Form Scale?

The Bristol Stool Form Scale is a GI & Liver scoring tool used in paediatric practice. Classifies stool form - used to characterise constipation and diarrhoea. It scores 1 criteria and interprets the total across 4 bands, so the number always arrives with the severity it implies rather than on its own. In PediAid each criterion is shown as a labelled option with the weight it carries, so the total can be checked rather than taken on trust.

2 When to use it

  • Grading severity at the bedside in GI & Liver
  • Recording an objective severity band in the case notes
  • Deciding when a total crosses the threshold for escalation
  • Re-scoring to track whether a child is improving or deteriorating
  • Checking the exact criteria of a score used infrequently

3 Formula & method

The score sums 1 criteria: Stool appearance. Totals are then banded: 1 type or more - Constipation: types 1-2 indicate constipation - hard, difficult to pass stools. Consider laxative therapy and dietary/fluid review; 3 type or more - Normal: types 3-4 are normal, with type 4 considered ideal; 5 type or more - Tending to loose: type 5 - lacking fibre; may indicate a tendency to loose stools or urgency; 6 type or more - Diarrhoea: types 6-7 indicate diarrhoea. Assess hydration, duration and infective causes; type 7 is entirely liquid.
  • A modified version for infants and toddlers exists, since breastfed infants normally pass loose stools.
  • Source: Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. Scand J Gastroenterol 1997;32:920-4.

4 Frequently asked questions

How many criteria does the Bristol Stool Form Scale use?

1. They are Stool appearance.

What do the bands of the Bristol Stool Form Scale mean?

The total is interpreted as: 1 type or more - Constipation: types 1-2 indicate constipation - hard, difficult to pass stools. Consider laxative therapy and dietary/fluid review; 3 type or more - Normal: types 3-4 are normal, with type 4 considered ideal; 5 type or more - Tending to loose: type 5 - lacking fibre; may indicate a tendency to loose stools or urgency; 6 type or more - Diarrhoea: types 6-7 indicate diarrhoea. Assess hydration, duration and infective causes; type 7 is entirely liquid.

Does the score replace clinical judgement?

No. It is a structured way to record and communicate severity. A clinician concerned about a child should act on that concern regardless of the total.

Where does this score come from?

A modified version for infants and toddlers exists, since breastfed infants normally pass loose stools.

Does it work offline?

Yes. Score definitions are bundled with the PediAid app, so the score computes without a connection.

For qualified clinicians. This page and the PediAid app are a clinical aid only. Calculations and reference data must be verified against the patient's clinical context, the source guideline and your local protocols before any treatment decision is made.