Bristol Stool Scale - Colitis

Bristol Stool Scale

In the world of Colitis and IBD, it's important that we learn as much about our disease as possible. Knowledge can help us make informed decisions about meds, diets, symptoms etc. So I decided to add a page about the Bristol stool scale, it's a useful bit of information to learn - especially for colitis sufferers.

What is the Bristol Stool Scale?

The Bristol stool scale (also referred to as the Bristol stool chart) is widely used and was developed in the City of Bristol in the UK. It is composed of seven types of stool, from dry to liquid, that are used to compare and help diagnose digestive problems and illness by comparison of consistency. It's also useful for helping patients communicate more clearly what they are experiencing.

It should be remembered that the chart is used for general examples e.g. outside of the explanations given, it's possible that there are other reasons why stool has a particular consistency.

What's the perfect stool?

It would appear that there are slight differences in opinion to what the perfect stool consistency should be, however the most popular description goes something like:

  • Approx 3 cm in diameter
  • Dark golden/yellow to brown in colour
  • Soft (but not too soft), like damp mud
  • Around 2 or 3 pieces with each bowel movement
  • Easy to pass with no pushing/straining
  • No feeling of the stool in the colon
  • No strong odour
  • Should contain around 75% water content

Checking your stool

After reading posts on Colitis forums and groups it appears that some IBDers don't pay much attention to their stool. Others have a quick look but find it a bit of a strange thing to do. In reference to colitis - I couldn't disagree more!!

Your stool can give you information about the state of inflammation; levels of absorption; types of food that cause problems or don't get absorbed; changes in bacteria levels etc. What appears to be a gross thing to do may actually help us make some positive changes, which is the reason I always do a visual check and write notes on stool consistency in my colitis diary.

Which stool in the Bristol chart is best?

As ever, when you start to look into this type of thing there's conflicting information. It appears that stool 4 and stool 5 are what most people consider the best place to be. Some think stool 4 is better than 5 and vice-a-versa however, I think as UCers we should be pleased to get near either.

Bristol Stool Chart

Stool 1

Consistency: separate hard balls or lumps (like nuts) which are difficult to pass.

Possible causes:

Constipation, stool spending too long in the colon.

Stool not retaining water because of lack of bacteria (can be due to a course of antibiotics).

Lack of fibre.

Possible results:

Abrasive texture of the stools can lead to bleeding in the rectal area.

Bristol Stool Chart 1 - Colitis

Stool 2

Consistency: hard balls or lumps stuck together, difficult to pass.

Possible causes:

Constipation, stool spending much longer in the colon than stool 1 (can be weeks) which leads to the hard lumps becoming compacted together.

Not going for a bowel movement when the body tells you to go.

Possible results:

The stool is made up of hard lumps compacted together which means it's larger than stool 1 and can cause excess straining, hemorrhoids and diverticulosis.

The size also means the abrasive texture of the stools are more likely to lead to bleeding in the rectal area.

Anal fissures can develop due to straining.

Because the stool is spending so much time in the large colon it fills the passage and is in contact with the colon walls meaning symptoms of Irritable Bowel Syndrome are more likely.

The small intestine can become obstructed because there is nowhere for the waste to go.

Note: supplementation with fibre is not a good idea in this situation because the the large colon is full and there is nowhere for the fibre to go, which could lead to an obstruction or perforation.

Bristol Stool Chart 2 - Colitis

Stool 3

Consistency: sausage shaped but with cracks on the surface.

Possible causes:

Can be a result of mild or undiagnosed constipation, stool can spend up to two weeks in the colon although it's smaller than stool 2 which indicates slightly more regular bowel movements.

Possible results:

Can cause symptoms of Irritable Bowel Syndrome.

Similar problems to stool 2 can develop such as anal fissures or hemorrhoids.

Bristol Stool Chart 3 - Colitis

Stool 4

Consistency: sausage / snake shaped, smooth and not too hard or soft - can be quite long e.g. banana or 'S' shaped.

Possible causes:

balanced diet, not in a flare-up

Possible results:

no straining required and very little wiping.

Note: This is considered a normal stool consistency when there is 1 bowel movement per day.

Bristol Stool Chart 4 - Colitis

Stool 5

Consistency: soft blobs with clear cut edges.

Possible causes:

balanced diet, not in a flare-up

Possible results:

Easy to pass.

Note: This is considered a normal stool consistency when there are 2 to 3 bowel movements per day.

Bristol Stool Chart 5 - Colitis

Stool 6

Consistency: fluffy pieces with ragged edges, a mushy stool - requires a lot of toilet paper.

Possible causes:

Inflammation

A reasonably fast digestive system

A rapid release of water and electrolytes resulting from stress

Rapid dehydration

Over use of mineral salts

Spicey foods

Possible results:

Mineral and vitamin deficiency due to a loss of too many electrolytes - common to Colitis where a lack of adequate dietary intake and inflammation in the colon means the body is unable to absorb the required amount of electrolytes.

Dhydration due to loss of water - common to Colitis where a lack of adequate dietary intake and inflammation in the colon means the body is unable to absorb the required amount of water.

Bristol Stool Chart 6 - Colitis

Stool 7

Consistency: Watery, no solid pieces - sometimes referred to as diarrhea.

However, I tend to associate diarrhea with a more extreme 'toilet session'. With colitis, I've had watery stools without the extreme symptoms of diarrhea - but this is IBD related e.g. excess mucus, and not what the Bristol Stool Chart is based on.

Possible causes:

Inflammation

Rapid dehydration

Over use of mineral salts

In reference to colitis:

Excess mucus

Food types that the system can't handle during a flare-up e.g. for me anything acidic such as lemon causes diarrhea.

Possible results:

Mineral and vitamin deficiency due to a loss of too many electrolytes - common to Colitis where a lack of adequate dietary intake and inflammation in the colon means the body is unable to absorb the required amount of electrolytes.

Dhydration due to loss of water - common to Colitis where a lack of adequate dietary intake and inflammation in the colon means the body is unable to absorb the required amount of water.

Bristol Stool Chart 7 - Colitis