One of the significant attributes of my hometown, besides the magnificent Clifton Suspension Bridge, is the fact that the famous Bristol Stool Chart originated here.

This chart contains seven categories that classify stool - from hard pellets resembling rabbit droppings to brown water. According to the chart, the ideal stool is the middle type 4: "like a sausage, smooth and soft".

In the early 2000s, a show aired on Britain's Channel 4 in which a nutritionist analyzed stool samples to comment on people's health, considering consistency, color, and smell. It can be said that Channel 4 probably paid well for that kind of job. Still, she was right.

There is no need to dissect your stool, but it is undeniable that the color and consistency of what we see in the toilet bowl or on the paper can give important information about our health.

Fifty Shades of Brown
The average healthy stool is, of course, brown. If you ever wondered, it is because of bile secreted by the liver into the intestines, which colors the stool that attractive shade of dull brown.

Stool consists of indigestible materials that the body cannot absorb. This includes solid components, such as proteins, fats, complex carbohydrates, and fibers, as well as some bacterial colonies from the intestines, but this varies between individuals depending on their diet and microbiome.

Stool is mostly water: on average, 75%. However, this also varies between hard, soft, and liquid stool, creating many different "recipes" for stool - in a range of brown shades. Dehydration - when the body loses more fluid than it takes in - can lead to hard stool that is difficult to pass. On the other hand, diarrhea can cause increased fluid loss and lead to dehydration.

So, if you are constipated or have very soft stool, it is important to drink enough water to stay well hydrated.

Changes in Color
Stool can be colored many other shades, and the causes vary in frequency and severity.

For example, green stool can result from consuming green vegetables or foods containing blue dye. Certain bacteria, such as salmonella, can color stool green. Bile, which is dark green, can be more visible in conditions that cause rapid stool transit through the intestines and diarrhea, such as viral infections.

You may also notice that your stool has an unusual color if the body cannot secrete bile into the intestines due to problems like gallstones or liver and pancreas diseases (including cancer) that block the bile ducts. Since one of bile's main roles is to break down and absorb fats, less bile means less fat absorption and more fat in the stool, giving it a pale yellow, white, or greasy/fatty appearance. Increased fat in the stool is called steatorrhea.

Red stool can be a disturbing sight. It may indicate bleeding from different parts of the intestines, from hemorrhoids to colon cancer. Blood changes appearance as it passes through the intestines, so it can look bright or dark red, and can be mixed with stool or cover the outer part of the stool.

If there is a problem with the upper part of the digestive tract (esophagus or stomach) - such as a bleeding ulcer, blood passes into the chyme (a mixture of digested food), changing its appearance to black, shiny, and sticky mass resembling tar. It also has a distinctive, unpleasant smell. This is called melena, and since it signals serious bleeding, it is a medical emergency.

Red or black stool can also be caused by food and dietary supplements, such as beets or iron and charcoal tablets. However, any change in stool appearance, like red, dark/black, or fatty yellow-white stool, should always be taken seriously and reported to a doctor as soon as possible. Large amounts of red bleeding or black, tar-like melena require an urgent visit to the hospital.

Baby Stool
When examining a newborn, the pediatrician will always ask the parents if their baby has passed urine and stool before being discharged home. It is unlikely that you will miss your baby's first stool. Every parent who has changed a diaper for the first time knows that it is an... interesting experience.

The first stool a baby produces, accumulated while in the womb, is dark, slimy, and green and is called meconium. The baby's first stool consists of old dead cells, mucus, and bile. One relieving thing is that it has no smell.

Meconium (fortunately) disappears with the start of breastfeeding. Breastfed babies' stools have a characteristic mustard-like appearance, while formula-fed babies' stools have a different smell. Baby stools vary in color, consistency, and volume as the intestines develop and with the introduction of solid foods.

Sometimes my daughter produced such sudden "poonamis" that we had to cut her out of her baby suits. It's all part of the rich tapestry of parenthood.

Additional Information on Stool Color
According to research, stool color can vary depending on many factors. For example, consuming certain foods or medications can temporarily change the color of stool. Consuming large amounts of beets, tomatoes, or blueberries can cause red stool, while consuming green vegetables, such as spinach or kale, can result in green stool.

Medications like antibiotics can also affect stool color. For example, certain antibiotics can cause diarrhea and changes in stool color due to changes in the gut flora. Iron supplements often cause darker, almost black stool, while some stomach acid-reducing medications can cause lighter, almost white stool.

Consuming activated charcoal, often used for body detoxification, can cause black stool. This is usually temporary and not a cause for concern, but if black stool persists for a long time or is accompanied by pain, it is recommended to see a doctor.

Stress and anxiety can also affect the color and consistency of stool. Stress can speed up or slow down digestion, which can result in diarrhea or constipation. Changes in digestion can cause changes in stool color, from lighter to darker shades of brown.

It is important to pay attention to long-term changes in stool color, as they can be a sign of serious health problems. If you notice persistent changes in stool color that are not related to diet or medications, contact your doctor for further testing.

Features of the Bristol Stool Chart
The Bristol Stool Chart is a tool that helps doctors and patients talk about stool without discomfort. The chart has seven categories describing different types of stool, from hard lumps (type 1) to watery stool without solid parts (type 7). The ideal stool, according to the chart, is type 4, which is smooth and soft, like a sausage.

Types 1 and 2 on the chart usually indicate constipation, while types 5, 6, and 7 indicate diarrhea. Types 3 and 4 are normal stool forms and indicate healthy digestion. Using this chart can help identify digestive problems and facilitate communication with a doctor.

The Bristol Stool Chart was developed at Bristol Royal Infirmary in England and has since become a standard tool in many medical facilities worldwide. This chart helps doctors quickly assess the health of a patient's digestive system and recommend appropriate treatments.

With the help of the Bristol Stool Chart, patients can better understand what is normal for them and when they need to seek medical help. This is especially useful for people with chronic digestive problems, such as irritable bowel syndrome (IBS) or Crohn's disease.

How to Maintain a Healthy Digestion
Maintaining healthy digestion is crucial for overall health. There are several steps you can take to improve the health of your digestive system:

1. Eat a balanced diet rich in fiber. Fiber helps maintain regular digestion and prevents constipation.
2. Drink enough water. Hydration is key to healthy digestion and helps prevent hard stools.
3. Exercise regularly. Physical activity stimulates digestion and can help reduce stress.
4. Avoid excessive consumption of alcohol and caffeine, which can irritate the digestive system.
5. Take probiotics. Probiotics help maintain a healthy gut flora and can improve digestion.
6. Reduce stress. Stress can negatively affect digestion, so it is important to find ways to relax.

By taking these steps, you can improve the health of your digestive system and reduce the risk of digestive problems. If you have persistent digestive issues, consult your doctor for advice and further testing.

Original:
Dan Baumgardt
Senior Lecturer, Department of Physiology, Pharmacology, and Neuroscience, University of Bristol