The Bristol Stool Chart is used to determine whether human stool (poop) is normal or abnormal based on its shape and how formed or loose it is. Healthcare providers use the chart to help diagnose gastrointestinal (GI) issues such as irritable bowel syndrome (IBS).
On the Bristol Stool Chart, stools are assigned a number from 1 to 7, from hardest to loosest. Normal stools are those in the middle of the chart, in the 3 to 4 range.
You may also hear the tool referred to as the:
- Bristol Stool Scale
- Bristol Stool Form Scale
- Meyers Scale
This article will discuss how the scale classifies stools, and how it is used by healthcare providers.
Bristol Stool Chart
The Bristol Stool Chart can help you decide when you need to see a healthcare provider for diarrhea or constipation. If you find that your stools are consistently ranking on either end of the scale, a healthcare provider can help you obtain a diagnosis and recommend treatment to improve your symptoms.
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, hard, 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 1 and 2
Types 1 and 2 describe stool that is hard to pass and may point to constipation. Stools of these types may be darker in color than normal stools.
Hard stools can have various causes, from a low-fiber diet and inadequate fluids to gastrointestinal conditions such as irritable bowel syndrome and Parkinson’s disease. Certain medications may also cause constipation as a side effect.
Bloating and stomach pains may go along with these types. Stools that are hard to pass can cause you to strain when trying to have a bowel movement and lead to diverticulosis and hemorrhoids.
Types 3 and 4
Types 3 and 4 describe stool that is well-formed and easy to pass. These are thought of as “normal,” healthy stools and the most ideal.
Types 5 and 6
These are loose stools. They can indicate a dietary problem, such as inadequate fiber intake, or they can happen as a result of an infection or other medical condition.
Type 5 stools are considered borderline diarrhea. For some people, they may be typical even in the absence of a gastrointestinal condition. For others, they may suggest a mild or developing gastrointestinal issue.
Type 6 stools are considered diarrhea even though they are not liquid. Diarrhea is often caused by a viral or bacterial infection, though it can also be a medication side effect or a symptom of a medical condition such as IBD or IBS.
Type 7 describes very loose stools or fully liquid diarrhea. With this type, you may feel an urgent need to have a bowel movement and may not be able to hold it. If the diarrhea persists, you may also become dehydrated or malnourished.
This type of diarrhea is most often caused by a viral or bacterial infection such as norovirus or E. coli. Parasitic infections such as Giardia lamblia can also cause watery diarrhea.
Certain medical conditions can cause type 7 stools as well, including celiac disease, Crohn’s disease, or ulcerative colitis.
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:
- 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.
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.
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:
- 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
Improving Bowel Health
Bowel health is closely related to diet and exercise. Often, simple changes like drinking more fluids, eating a diet high in fiber, and exercising regularly will help you achieve easy to pass stools. It’s also a good idea to pay attention to the foods you eat. For some people, fatty foods, alcohol, and caffeine may lead to changes in your stools.
If you’re taking a new medication, talk to your healthcare provider about any changes in your stool. If your medication is causing diarrhea or constipation, you may be able to change the dose or switch to a different medication.
If lifestyle modifications don’t help, try training your body to have a bowel movement on a regular schedule. You can start by sitting down on the toilet at the same time every day, even if you don’t think you need to go. Often, getting on a regular schedule can help normalize your bowel movements and make them easier to pass.
Sitting correctly on the toilet can also help you avoid straining. Try to relax, straighten your spine, and lean forward. It may also help to keep your knees higher than your hips. This may mean using a footstool.
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.
Frequently Asked Questions
Should I be concerned about floating stool?
On its own, floating stool isn’t always something to be concerned about. It could just mean your body has excessive gas. This can happen from switching up your diet.
However, floating stool has also been linked to malabsorption (not absorbing enough nutrients from food), an infection in the gastrointestinal system, pancreatitis, and mixed irritable bowel syndrome. It may be worth contacting your healthcare provider if you experience unexpected or severe weight loss.
How does diverticulosis affect stool?
Diverticulosis affects stool by making the stool hard and difficult to pass, which may result in constipation and it can also be the result of underlying constipation. It commonly causes bleeding from the rectum, but this bleeding is often painless. After a bowel movement, the stool can show signs of bright red or maroon-colored blood.
How does colon cancer affect stool?
Colon cancer affects stool by changing its consistency, shape, and color. These changes could be one of the first signs of colon cancer. Stool may appear very thin and cause pain, cramping, and bleeding. A change in bowel movements, in which you need to go more often or less frequently, can also happen.
What causes type 6 on the Bristol stool scale?
Type six on the Bristol stool scale can be caused by mild diarrhea and a lack of fiber. Usually mild diarrhea will clear up on its own, but if it doesn’t appear to get better after a few days, a healthcare provider can help treat the issue.