Lady sat on the toilet

What Your Poo Tells You About Your Gut Health

Checking your poo can tell you a lot about what’s going on in your gut. We asked dietitian Laura Tilt for the lowdown on stool gazing.

A lesson in stool gazing

How often do you check your poo? If gazing into the loo after you poo isn’t something you’re in the habit of doing, I’m here to persuade you to take a look. That’s because your poo is a helpful (and visible) indicator of what’s going on in your gut, providing insights like whether you might benefit from eating more fibre or if there might be an issue with your digestion.

It’s also important to know what’s normal for you in terms of your poo, as changes in your poo (like how often you’re going or what your poo looks like) should be checked by your G.P. if they last for three weeks or longer. So, let’s get to it.

What is poo anyway?

About 75% of poo is water. The solid fraction is made up of a mix of undigested fibre, bacteria (both living and dead), old red blood cells and bile, which gives poo its brown colour.

Different factors affect how often and how much you poo, but one of the biggest determinants is how much fibre you consume. Fibre adds bulk to poo and holds water, which makes stools softer and easier to pass. Fibre also shortens transit time (the time it takes for food to travel through the gut) helping to prevent constipation.

Ok, so how do I decode my poo?

There are a number of things you can take note of when it comes to translating your poo, including its colour and appearance, how often you’re going, and how easy it is to have a poo. Let’s take a look at each.


Poo is typically a shade of brown, which is down to a combination of bilirubin (a yellowish substance made when the body breaks down old red blood cells) and bile, a substance produced by the liver which helps to digest fats. As the bile and bilirubin move through the gut, they are converted into compounds which are brown - and this is what’s responsible for the colour of poo.

So what does it mean if your poo isn’t brown? Some foods can temporarily change the colour of your poo such as beetroot or blue food dye. Red or black in your stool can indicate bleeding somewhere in your gut. If you experience this you should speak to your G.P. - it’s often not serious but they can check the cause.

Pale or clay coloured poo can indicate a problem with the flow of bile into the gut, whereas yellow, greasy stools can suggest a problem with absorption and digestion of fats. If changes in the colour of your poo persist, speak to your G.P.


When it comes to the look of your poo, health professionals often refer to Bristol Stool chart (BSC) - a visual scale which categorises different types of stools. It was developed in the 90’s by researchers at Bristol Royal Infirmary and can help to identify how long the stool has been in the large intestine (colon).

the Bristol Stool chart
The chart shows seven types of stools. Stool types 1-2 are dry, hard stools which have spent the longest time in the colon. They tend to be difficult to pass, usually resulting in straining and pain. These types of stools indicate constipation. There are many factors that can contribute to constipation, but as a first step, check that you are drinking enough fluid and eating plenty of fibre. Regular exercise can also help.

Stool types 3-4 are considered normal stools - they are soft and easy to pass, and don’t cause irritation.

Stool types 5-7 are stools with increasing water content, with type 7 indicating diarrhoea. This is a stool which has moved through the colon very quickly, before water can be reabsorbed. Diarrhoea can be due to illness like food poisoning, digestive conditions like irritable bowel syndrome, or an inability to digest a particular component of a food (such as lactose). Looser stools are also common around the menstrual cycle (due to hormones) and can be a response to acute anxiety or nerves.


Pooing anywhere from three times a day to three times a week is considered normal. Whilst this seems like a huge spectrum, it shows the natural variation in transit times between individuals. It’s normal to get the urge to have a poo after a meal, thanks to something called the gastrocolic reflex. This is a muscular contraction which moves food through the gut in response to eating, typically about 20-30 minutes after a meal. In one study of UK adults, the majority of poos were recorded in the morning between 6 and 10 AM. This could be down to breakfast and coffee drinking, which has been shown to increase muscular activity in the colon.


One marker of a healthy poo is being able to poo swiftly and without pain. Ideally you shouldn’t be straining on the toilet or struggling to pass a stool - this can be due to poos which are hard and dry or because the pelvic floor muscles are not relaxing properly. Raising your feet off the floor with a small stool (so that you are in more of a squatting position) can make pooing easier.

Another clue to a healthy poo is feeling that you have emptied your bowels after a poo. If your poo feels incomplete or you have to go back to the toilet soon after to have another poo then speak with your G.P.

Is there such a thing as a perfect poo?

A type 4 stool on the Bristol stool chart is sometimes referred to as the ‘perfect poo’ - it’s soft and easy to eliminate! However, it’s important to remember that you won’t have the same type of poo every time - changes in diet, hydration and travel can all impact your poo temporarily.

What’s important is knowing what’s normal for you, and then taking action if your poo is causing you pain, discomfort or if you notice a change that isn’t usual for you. If you have a change (for example you’re going more or less often than normal) that lasts longer than a couple of weeks then speak with your G.P.

Lastly a reminder that pooing is necessary, natural and something we all do. Normalising conversations about poo is really important in reducing the stigma that might prevent us from seeking help when something is up. Getting familiar with your poo is also a key part of learning more about your gut health.


Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. Scand J Gastroenterol. 1997;32(9):920-924. doi:10.3109/00365529709011203

Rose C, Parker A, Jefferson B, Cartmell E. The characterization of feces and urine: A review of the literature to inform advanced treatment technology. Crit Rev Environ Sci Technol. 2015;45(17):1827-1879. doi:10.1080/10643389.2014.1000761

Looking for more?

Go back to gut basics with Dr Chris George