The Bristol Stool Form Scale (BSFS), commonly known as the Bristol Stool Scale, is a chart used to categorise stools into seven types based on their consistency. This classification helps determine whether a bowel movement is healthy.
The bowel plays a key role in digestion by absorbing nutrients from food and expelling waste that the body doesn’t need. When stool passes through the bowel too quickly or too slowly, it could signal an underlying issue with bowel function.
This guide overviews the BSFS and offers practical tips for enhancing bowel health and function.
What Is the Bristol Stool Chart?
Your poop can reveal a lot about your health, but explaining your bowel movements (BMs) to a doctor without bringing a physical sample can be challenging. That’s where the Bristol Stool Scale, also known as the Meyers Scale, comes in handy.
This tool uses pictures and short descriptions to classify stool types, providing a simple way to discuss the appearance and texture of poop—what medical professionals refer to as stools. By examining stool types, doctors can estimate how long it takes for food to move through your digestive system and identify potential digestive issues.
The BSFS was developed based on research by Dr. Stephen Lewis and Dr. Kenneth Heaton at Bristol Royal Infirmary in the UK. In a notable 1997 study, 66 adult participants kept diaries documenting the appearance and frequency of their stools. To help the research, participants swallowed marker pellets to measure digestion time, and their stool samples were weighed. Additionally, medications were used to alter stool consistency and digestion speeds, ensuring diverse conditions were studied.
Today, this chart is widely used in clinical settings, particularly by healthcare providers specialising in digestive health.
Bristol Stool Chart
The Bristol Stool Form Scale (BSFS) categorises stool types from the hardest to the softest. Experts regard types 1 and 2 as abnormally hard, often signifying constipation, whereas types 6 and 7 are considered overly loose and may suggest diarrhoea. Healthcare professionals consider types 3, 4, and 5 the most common.
Bristol Stool Chart PDF
Keep this chart handy to better understand your stool type and track your digestive health.
[Download Bristol Stool Chart PDF]
Types of Stool Forms (1 to 7)
Understanding the different types of stools on the Bristol Stool Chart can help you identify what’s normal, what’s not, and how it relates to your digestive health.
Type 1 stool
If you notice hard, separate pellets of stool that are difficult to pass, this indicates severe constipation. This means your stool is taking a long time to move through your digestive system. As a result, more water that would normally be included in your stool is absorbed by your colon, leading to drier and smaller stools. The most common reasons for this are insufficient fluid and fibre intake in your diet. Medications, stress, and illness can also contribute to this issue.
Type 2 stool
These hard, lumpy stools are slightly larger but still indicate constipation and often stem from inadequate fluid and fibre. In addition to adjusting your diet, increasing physical activity might help move things along.
Type 3 stool
A sausage-shaped stool with cracks on the surface is generally considered normal according to the Bristol Stool Scale.
Type 4 stool
A thinner, more snake-like stool that is smooth and soft is also seen as normal under Bristol criteria.
Type 5 stool
If you are producing soft blobs of stool with distinct edges, you are nearing diarrhoea. Surprisingly, the issue could stem from insufficient fibre intake, as fibre assists in solidifying your stool.
Type 6 stool
Passing fluffy, mushy pieces of stool with jagged edges indicates diarrhoea. This suggests that your food is moving quickly through your digestive system, leaving your colon with insufficient time to absorb water and create firmer stools. You might be experiencing a viral infection like norovirus, food poisoning, or other digestive problems. Stress might also contribute to this condition.
Type 7 stool
Watery stools without solid pieces are signs of severe diarrhoea. Most diarrhoea attacks last a day or two and resolve on their own. However, if you frequently have this kind of stool or type 6 stool, consult your doctor. Chronic diarrhoea can signify conditions that cause irritation or inflammation of the intestines, such as irritable bowel syndrome, Crohn’s disease, or ulcerative colitis.
Normal Poop
Let’s explore what normal poop is like:
- Colour: Medium to brown colour
- Odour: Strong smell
- Pain: Normal poop is pain-free and it takes minimum strain
- Texture: It’s firm to soft and pass smoothly in a few smaller pieces or a single piece.
- Frequency: it should be once or twice a day. Most people pass once a day but for some people it twice or thrice a day.
Are you unsure if your poop is normal? [Download the Bristol Stool Chart PDF] for easy comparison.
How long should a normal poop take?
It should take between 10-15 min. But if you are taking too long, it can be a sign of constipation, haemorrhoids or any other condition.
If you are facing the same issue, try the best toilet position to relieve constipation or consider natural foods that are good for constipation.
What Do Different Poop Colours Indicate?
While brown is generally the healthiest colour for poop, changes in stool colour can occur due to diet, medication, or potential health issues. Here’s what different colours may signify:
Green: May result from certain foods or antibiotics, but could also indicate an infection or digestive disorder.
Yellow: Normal in breastfed babies but can occasionally be linked to diet in adults.
Orange: Often caused by certain foods but may also suggest malabsorption issues.
Black: Black or Tarry stool can occur due to medications or foods like blueberries, but might signal bleeding in the upper digestive tract.
Red: Bright red stools may result from red-coloured foods or indicate bleeding in the lower digestive tract.
If you notice blood in your stool or experience pale, chalky stools—common with pancreatitis—contact your doctor immediately. Learn more about what causes blood in the stool.
A Quick Recap on Bristol Stool Chart
The BSFS is a tool used for diagnosing that allows individuals to categorize their stools by their physical characteristics. The scale ranges from type 1 (hard) to type 7 (loose) and can help identify issues with bowel movements based on stool shape and consistency.
Using the results, your doctor can evaluate your bowel habits and patterns and may recommend additional tests to determine the underlying cause of your gastrointestinal problems.
Additionally, the scale serves as a research tool to investigate gastrointestinal disorders and the effectiveness of different treatments for these conditions.
Frequently Asked Questions
1. What type of stool should raise concern?
Stools that are black or reddish may indicate gastrointestinal bleeding and should not be ignored. Similarly, grey stools might point to liver issues, while yellow, greasy, and foul-smelling stools suggest poor fat digestion and absorption in the intestines.
2. What is the ideal stool type according to the bristol stool chart?
The most ideal stool types are type 3 and type 4 on the Bristol Stool Chart. These stools are smooth, easy to pass, and indicate healthy bowel habits and digestion.
3. What does the stress-induced poop look like?
Stress-related stools are often pale, foul-smelling, and may float in water.
4. What defines abnormal stool?
Abnormal stools can include:
- Frequency: More than three bowel movements daily or fewer than three per week.
- Form: Stools that are hard and lumpy or loose and watery.
5. What stool colours are unhealthy?
Stools that are bright red or black may signal blood in the stool and should prompt immediate medical attention. Pale or clay-coloured stools might indicate digestive or liver issues, while rapid food transit may result in abnormally coloured stools.
6. How can you tell if your stool is healthy?
Healthy stools are smooth, sausage-shaped, and easy to pass. If stools are hard and lumpy, it could be a sign of constipation, which may improve with increased water intake and fibre-rich foods like fruits, vegetables, nuts, and beans.
