The Bristol Stool Scale (also known as the Meyers Scale) is used to describe seven shapes and types of stools (poop), ranging from ranging from type 1 (hard lumps) to type 7 (watery diarrhea).
The scale can be used to measure the time it takes for food to pass through your body and leave as waste, as well as point your doctor toward a diagnosis of some digestive problems. The chart was developed in 1997 by researchers from the University of Bristol (Lewis & Heaton, 1997).
Equipment required: a stool scale (see below), with images and description of seven types of stool. There is also a modified Child Bristol Stool Form Scale (mBSFS-C) which reduces the number of options to five (Lane et al. 2011).
Instructions: When passing a bowel movement, patients should visually assess the appearance and consistency of their stool and match it to the corresponding category on the scale. Record the results immediately after each motion.
Adult Bristol Stool Form Scale (BSFS)
These descriptors are usually placed alongside images of each stool type. Search online for examples.
- 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
Results: The ideal stool is generally type 3 or 4. The Rome III criteria is used to classify abnormal stool, with stool types 1 and 2 designated as constipation, types 3, 4, and 5 as normal stool form, and types 6 and 7 as diarrhea
References:
- Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. ScandJ Gastroenterol. 1997;32:920–924.
- Lane MM, Czyzewski DI, Chumpitazi BP, Shulman RJ. Reliability and validity of a modified Bristol Stool Form Scale for children. J Pediatr. 2011;159:437–441 e431.