Bristol Stool Form Scale

Stool Form

Stool Type: 1

Type 1 - Severe Constipation

Separate hard lumps, like nuts. Difficult to pass. Indicates significant constipation and prolonged transit time.

Classifies stool (correlates with intestinal transit time).

Why Use

Standardizes stool descriptions in clinical and research communications. Offers a validated, visual reference to classify stool consistency. Helps correlate stool form with colonic transit time and possible underlying pathology.

When to Use

Can be used when evaluating patients with suspected or known gastrointestinal complaints or changes in bowel habits (e.g., diarrhea, constipation, IBS). Can assist in monitoring stool consistency over time or in response to treatment.

Formula

Selection of the appropriate type:

Pearls / Pitfalls

Not intended to be a diagnostic tool; classification should be interpreted within the clinical context. Verbal descriptors can lead to subjective patient reporting and inconsistencies; use the visual aids when possible. Stool form can fluctuate based on diet, hydration, and stress; emphasize the importance of patterns over single-event changes.

Advice

If stool patterns suggest potential pathology (persistent type 1–2 or 6–7): Investigate further with lab tests or imaging, as appropriate. Assess for diarrhea- or constipation-inducing medications; consider adjustments or alternatives. Advise changes in fiber intake, hydration, and exercise. If chronic changes persist or red-flag symptoms appear (e.g., GI bleeding, significant weight loss), escalate care to gastroenterology.

More Information

Interpretation: Bristol Stool Scale Type Interpretation 1-2 Associated with constipation 3-4 Normal 5 Associated with diarrhea to some degree 6-7 Associated with diarrhea From Lacy 2017 .