An Overview of the Bristol Stool Chart

A diagnostic scale used to assess feces

The Bristol Stool Chart is a tool used to assess human stool (poop) based on its shape and how formed or loose it is.

You may also hear the tool referred to as the:

  • Bristol Stool Scale
  • Bristol Stool Form Scale
  • Meyers Scale

Stools are assigned a number from 1 to 7, from hardest to loosest.

The scale was created in 1997 by a team of healthcare providers at the British Royal Infirmary in Bristol, England.

It has since become a useful tool to help diagnose gastrointestinal (GI) issues such as irritable bowel syndrome (IBS).

This article will discuss:

  • How the scale classifies stools
  • How it is used by healthcare providers
  • How and why it is used in research
bristol stool chart
Verywell / Jessica Olah

Bristol Stool Scale

Your healthcare provider will likely ask you to look at the chart and point to the number that most closely matches the look and form of your bowel movements:

  • Type 1: Separate hard lumps (hard to pass)
  • Type 2: Lumpy, sausage-shaped
  • Type 3: Sausage-shaped with cracks on the surface
  • Type 4: Sausage-shaped or snake-like; smooth and soft
  • Type 5: Soft blobs with clear-cut edges (easy to pass)
  • Type 6: Fluffy pieces with ragged edges; mushy
  • Type 7: Entirely liquid, watery, no solid pieces

Types 3 and 4 describe stool that is well-formed and easy to pass. These are thought of as healthy and the most ideal.

Types 1 and 2 describe stool that is hard to pass and may point to constipation. Bloating and stomach pains may go along with these types.

You may have trouble passing your stool fully. This can cause you to strain when trying to have a bowel movement and lead to hemorrhoids.

Types 5 and 6 are loose stools that can indicate either a lack of fiber in the diet or mild diarrhea.

Type 7 describes very loose stools or fully liquid diarrhea. You may feel an urgent need to have a bowel movement and may not be able to hold it with this type.

You may also become dehydrated or malnourished if the diarrhea persists.

Recap

Your stool is classified based on a 7-point scale that describes its shape and consistency. This can point to GI issues such as constipation and diarrhea.

How the Bristol Stool Chart Is Used

Your healthcare provider may use the Bristol Stool Chart if you have unusual bowel symptoms or notice a change in your bowel habits or the way your stools look.

These include issues such as:

  • Diarrhea
  • Constipation
  • Switching between diarrhea and constipation
  • Abdominal cramps
  • Bloating and gas
  • Nausea or fullness
  • Steatorrhea ("greasy" floating stool)
  • Other symptoms that point to malabsorption, or an inability to digest and absorb nutrients

Your healthcare provider may ask you to look at your stool and compare it to the Bristol Stool Chart. You can then talk about any changes to your bowel habits and the new score at your next visit.

During your visit, your healthcare provider may ask you how often you tend to have a bowel movement and whether you have been having them more or less often than usual.

They may also ask you other questions about your stool such as:

  • How much you tend to pass with each bowel movement
  • How your stools tend to smell and what color they most often are
  • Whether you notice blood or mucus in your stool
  • Whether your stools stick to the toilet bowl and how easy it is to flush away all stool remnants

Your healthcare provider may also look at a sample of your stool and order other tests as needed. For example, they may do a stool culture to find out what kind of bacteria, if any, are present in stool.

They may also use the Rome Criteria to see if your symptoms match those of a functional gastrointestinal disorder such as IBS.

Bowel movements are considered regular in most cases if they occur as often as one to three times a day, or as little as three times a week. But what is considered a "normal" bowel movement varies with each person and there are many factors that influence bowel habits.

A person's bowel habits are influenced by many factors and can change day to day.

For instance, your bowel habits may shift due to:

  • Diet
  • Stress
  • Travel
  • Dehydration
  • Medicines
  • Changes that occur as you age
  • How active you are or how much you exercise
  • Illness such as the stomach flu
  • Changes in your hormone levels, such as those that occur when you are pregnant or menstruate
  • More serious health issues such as inflammatory bowel disease or colon cancer

Recap

Your healthcare provider uses this tool as part of a more thorough assessment of your bowel patterns and habits. This can help pinpoint what may be causing GI issues or making them worse. The results may also point to the need for more tests to determine the root cause of these problems.

Bristol Stool Chart in Research

The Bristol Stool Chart is often used in research as a way to measure how quickly food passes through the digestive tract, and to study problems with GI function.

Researchers have also used the chart to assess how well various treatments work for people with certain GI issues.

And the scale has been used in studies looking at alternative treatments such as acupuncture.

A modified version of the chart can also be used for children. It includes drawings that children can use to describe their stools when being assessed for bowel issues such as constipation and soiling.

Summary

The Bristol Stool Chart is a tool used by your healthcare provider to assess your stool. The 7-point scale helps describe your stool shape and consistency.

Based on the results, your provider can assess your bowel patterns and habits and order more tests as needed to figure out what may be causing your GI issues.

The scale is also used as a research tool to explore GI disorders and how well various treatments work for these issues.

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6 Sources
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