ToolsCalculators
Bristol Stool Form Scale
Seven-category classification of stool consistency reflecting colonic transit time.
Bristol Stool Form Scale
Stool appearance
ResultType 1
Suggests slow colonic transit / severe constipation.
- Bristol type
- 1
When to use
- Standardising the description of stool consistency in clinical notes, trials, and bowel diaries.
- Screening tool referenced by the Rome IV criteria for irritable bowel syndrome subtyping.
Formula
A 7-point ordinal descriptive scale from type 1 (hardest) to type 7 (most liquid); there is no summed score.
Pearls and pitfalls
- Correlates well with whole-gut transit time: harder stools (types 1-2) reflect slower transit, looser stools (types 6-7) faster transit.
- Types 3-4 are generally considered the easiest to pass and 'normal'.