Bristol stool scale

diagnostic medical tool designed to classify the form of human faeces into seven categories

The Bristol stool scale is a medical diagnosis tool used by doctors to classify the way feces looks into 7 different categories.[1] It is also known by the names, Bristol stool chart and Bristol stool form scale.

Bristol stool chart

It was developed at Bristol Royal Infirmary in 1997 as a clinical assessment tool, but is also used to help with patients who can't speak, so that they can show their doctor if they have a problem with their bowels (a clinical communication aid). It's also used to help diagnose Irritable Bowel Syndrome (IBS).

Understanding the scale


The seven types of feces described by the scale are:

  • Type 1: Separate hard lumps, like nuts (hard 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
  • Type 5: Soft blobs with clear cut edges (passed easily)
  • Type 6: Fluffy pieces with ragged edges, a mushy stool
  • Type 7: Watery, no solid pieces, entirely liquid


  1. Koh, H.; Lee, MJ.; Kim, MJ.; Shin, JI.; Chung, KS. (February 2010). "Simple diagnostic approach to childhood fecal retention using the Leech score and Bristol stool form scale in medical practice". J Gastroenterol Hepatol. 25 (2): 334–8. doi:10.1111/j.1440-1746.2009.06015.x. PMID 19817956. S2CID 46258249.