Bristol stool scale

The Bristol stool scale is a diagnostic medical tool designed to classify the form of human faeces into seven categories. It is used in both clinical and experimental fields.

It was developed at the Bristol Royal Infirmary as a clinical assessment tool in 1997, by Stephen Lewis and Ken Heaton and is widely used as a research tool to evaluate the effectiveness of treatments for various diseases of the bowel, as well as a clinical communication aid; including being part of the diagnostic triad for irritable bowel syndrome.





== Interpretation ==

The seven types of stool are:



Type 1: Separate hard lumps, like nuts (difficult to pass)

Type 2: Sausage-shaped, but lumpy

Type 3: Like a sausage but with cracks on its surface

Type 4: Like a sausage or snake, smooth and soft (average stool)

Type 5: Soft blobs with clear cut edges

Type 6: Fluffy pieces with ragged edges, a mushy stool (diarrhea)

Type 7: Watery, no solid pieces, entirely liquid (diarrhea)

Types 1 and 2 indicate constipation, with 3 and 4 being the ideal stools as they are easy to defecate while not containing excess liquid, and 6 and 7 indicate diarrhea.

In the initial study, in the population examined in this scale, the type 1 and 2 stools were more prevalent in females, while the type 5 and 6 stools were more prevalent in males; furthermore, 80% of subjects who reported rectal tenesmus (sensation of incomplete defecation) had type 7. These and other data have allowed the scale to be validated. The initial research did not include a pictorial chart with this being developed at a later point.

The Bristol stool scale is also very sensitive to changes in intestinal transit time caused by medications, such as antidiarrhoeal loperamide, senna, or anthraquinone with laxative effect.





== Uses ==





=== Diagnosis of irritable bowel syndrome ===



People with irritable bowel syndrome (IBS) typically report that they suffer with abdominal cramps and constipation.

In some patients, chronic constipation is interspersed with brief episodes of diarrhoea; while a minority of patients with IBS have only diarrhoea.