Updated 27th July 2023
Fascinating insights from The Big Poo Review
Recently, ZOE conducted the largest survey into bowel habits that the world has ever seen.
The Big Poo Review – in partnership with Steph’s Packed Lunch, on Channel 4 – provides a first-of-its-kind sneak peek into the bathrooms of Britain.
Our scientists have finished crunching the numbers, so today, we’ll lay out some of the most interesting insights.
We cover farts, how long people spend on the toilet, diarrhoea, constipation and more.
First up, a snapshot of who took part.
Who got involved?
In total, 142,768 people in the United Kingdom aged 18 or older took part, including 110,627 females, 32,023 males and 118 people who selected ‘other’.
The top locations were Leeds, with 1,585 respondents; Wiltshire, with the same number; and Cornwall, with 1,363 participants.
This was the age distribution of our contributors:
18–32 years: 6,944
33–43 years: 14,853
44–57 years: 43,888
58 and older: 76,886
So, what fascinating observations did we make from this wealth of data?
How often do we poo?
Everyone’s body is different, so it’s no surprise that some of us poo more often than others.
According to experts, pooing anything from 3 times a day to 3 times a week is within the normal range. Our survey showed that a reassuring 92.7% of people fall within it.
We also found that, on average, people in the U.K. poo 1.66 times a day. And there was no difference in the poo rates of males and females.
Those in the 18–32 age group pooed the most often: 1.72 times a day.
When we look at how often individuals reported pooing – more than half of us poo once a day (54%), while 0.38% poo just once a week, and 1.38% poo more than four times a day.
Breaking down the data by region, we found that people in Thanet, Kent, poo most frequently, at an average of 1.86 times a day. At the other end of the scale, people in Bridgend, Wales, do an average of 1.49 poos a day.
What time do we poo?
Most of us – 60.7% – poo after breakfast, and 32.9% poo just after waking up.
Some of this might be due to your morning cup of coffee or breakfast stimulating the gastrocolic reflex to get things moving.
Interestingly, there were no significant differences between males and females or among the age groups. So, when it comes to the timing of our poos, most of us are early birds.
But a fairly large proportion of people (17.1%) said they poo at ‘random’ times. And this was more common in females than males – about 18% versus 12%.
How common is constipation?
We found that constipation is surprisingly common. We defined it as pooing three times a week or less often – or passing Bristol Stool Scale types 1 or 2 poos more than 25% of the time.
Type 1 poos are separate hard lumps, like nuts. And type 2 poos are like lumpy sausages. Here's the scale:
More than 21% of participants reported constipation, and it was significantly more common among females. Constipation affected just 13% of males but more than 23% of females.
Dr Will Bulsiewicz, ZOE’s U.S. medical director and a board-certified gastroenterologist, explains that there could be a number of reasons for this difference. Some include:
Females have longer bowel transit times, which is the time it takes food to move through your bowel.
Female sex hormones – for example, progesterone – can slow bowel motility.
Constipation is more common after menopause.
Comparing regions, we found that Shepway, Kent, has the most people with constipation (27.8%) and the Scottish Borders area has the fewest (13.4%).
What about diarrhoea?
Diarrhoea was also common, though less common than constipation. In all, 15.3% reported pooing more than three times a day or passing types 6 or 7 poos more than 25% of the time.
Type 6 poos are mushy, fluffy pieces with ragged edges, and type 7 are watery, with no solid pieces.
The sex differences here were less pronounced than with constipation, but males were slightly more likely to report diarrhoea than females: 17.5% versus 14.7%.
According to Dr B, some studies suggest that males are more likely than females to develop irritable bowel syndrome (IBS) with diarrhoea.
Also, as we described above, there are a few reasons why females are more likely to experience constipation. So, it makes sense that they’re less likely to have diarrhoea.
Regionally, Carmarthenshire, Wales, had the highest rates of diarrhoea (20.5%) and Hertsmere, Hertfordshire, had the lowest (10%).
Constipation and diarrhoea: Tips from Dr B
According to Dr B: “One of the superpowers of fibre is that it’s beneficial to both constipation and diarrhoea. It helps to drive you towards normal, healthy bowel movements. This is important because treatments that treat constipation can easily overshoot and cause diarrhoea, or vice versa."
He continues: "It’s not fun to be on a bowel movement rollercoaster. Regular, healthy, satisfying bowel movements is where we want to be, and fibre helps us get there.”
For people with diarrhoea, fibre helps firm up your stool; for people with constipation, it helps move the poo through your bowel.
Also, as you up your fibre intake, Dr B reminds you to increase your fluid intake.
For constipation, green kiwis and prunes can help move things along. Also, magnesium supplements can help keep you more regular. As for diarrhoea, the first step is to identify why you’re having it.
If you have IBS with diarrhoea, some foods can make things worse. These include fried foods, fatty foods, dairy, gluten or wheat-based foods, chocolate, caffeine, and carbonated drinks. So, moderating these might help.
How long do you spend on the loo?
The Big Poo Review has found that, on average, we spend 3.53 minutes on the loo. And, once again, there’s a difference between males and females.
Males tend to sit on the porcelain throne longer than females – 5.26 minutes, compared with 3.53 minutes.
Why is this? According to Dr B, “There’s no physiological or anatomical reason” for this difference. He suggests that there may be some kind of social aspect, but we don’t know exactly what.
And looking at differences between age groups, it seems that we sit on the loo for less time as we age.
Those aged 18–32 spent the longest, with an average of 5.41 minutes. The oldest age group, 58 and over, spent just 3.68 minutes on the loo.
Dr B wonders whether younger people might be more likely to take their phones into the bathroom and spend a bit of time scrolling, while older adults are generally less obsessed with their smartphones.
But at this point, we don’t know why we see this difference across age groups.
Now let’s look at regional differences. Individuals in East Lothian, Scotland; South Lakeland, Cumbria; and Hackney, London, spend the least time pooing.
And people in Westminster, London; Sunderland, Tyne and Wear; and Hull, East Yorkshire, spend the longest.
Before you ask, the survey used people’s home postcodes, not their work postcodes, so this doesn’t (necessarily) mean that members of parliament spend a lot of time on the loo.
There were some interesting results at the extreme ends of the spectrum: 4.9% of you spend 30 seconds or less on the loo, and 6.5% spend more than 10 minutes.
According to Dr B, spending extra time isn’t ideal. This is because blood moves into the tissue surrounding your bottom as you squat, which can exacerbate haemorrhoids.
“You don’t want to strain or push, you want to allow it to happen naturally. But you also want to get your business done and move on with your day.”
What about IBS?
IBS is a common condition characterised by stomach cramps, bloating, diarrhoea and constipation. The symptoms can come and go or last for days – or even weeks.
As part of The Big Poo Review, we investigated how common this condition is in the U.K. We found that 17.1% of respondents had received an IBS diagnosis.
And males and females experienced the condition at different rates: 10.1% and 19.1%, respectively. So, women are around twice as likely as men to have IBS, which is in line with previous research.
Regionally, East Dunbartonshire, in Scotland, had the highest rates (25.3%), and Harborough, in Leicestershire, had the lowest (9.2%).
When we break it down by age, we found that people aged 33–43 were most likely to experience it, with 21% reporting an IBS diagnosis.
How often do you fart?
Although it’s frowned upon in many circumstances, breaking wind is natural and healthy. But how often do we do it?
According to The Big Poo Review, females fart an average of 8 times a day, and males break wind an average of 9 times a day.
But there’s a fair amount of variation. For instance, 1% of our respondents reported farting more than 40 times a day.
According to Dr B, if this is you, it’s worth chatting with your doctor, who can check for an underlying condition.
Meanwhile, 1.6% report that they never pass wind. Dr B tells us that this is unlikely. Everyone farts (except his wife).
We also found that the 18–23 age group break wind most often (9.8 times per day) and those aged 58 or older fart the least (7.3 times a day).
According to Dr B, this is the opposite of what he would expect. He hopes to dig deeper into the data to try and unravel this conundrum.
So, which area of the U.K. farts the most? The windiest region is North Lanarkshire, in Scotland, with an average of 10 farts per day. And the least windy is Telford and Wrekin, in Shropshire, at 6.7 times per day.
In regions with the highest flatulence rates, 58% of respondents felt that farting wasn’t a problem. This might help explain why they weren’t shy about reporting a higher rate of wind. Let it go, let it flow…
And if you’re wondering, ZOE has an article on how your rectum tells the difference between gas and solid. It’s a common question that most of us aren’t willing to ask aloud.
Passing gas: Tips from Dr B
Farting is normal and healthy, so you shouldn’t bottle it up. However, some respondents reported that it interferes with daily life. This could be from embarrassment or because of the smell or noise.
If this is you, Dr B has some tips. He suggests trying two or three of these:
Cut out straws, chewing gum or sweets, and carbonated drinks. Slow down at mealtimes, and have controlled swallows.
Make sure you’re not constipated. If you are, try a treatment. You’ll be amazed at how much your flatulence will improve. Check out the ZOE Science & Nutrition podcast on constipation for more information.
Reduce your intake of fermentable foods. A good place to start is to eliminate dairy products and artificial sweeteners. Sometimes, a doctor might suggest that you try the low FODMAP diet.
Add more probiotics to your diet. You could do this with fermented foods, including kefir and yoghurt. In some cases, a probiotic supplement can help, as well.
If you have any further concerns, speak with your doctor.
As you can see, The Big Poo Review provided some incredible insights into the bowel habits of the U.K. Let’s end with a quick recap of some findings:
We poo an average of 1.66 times a day.
Most of us poo not long after waking up.
Constipation is common, particularly in females.
Diarrhoea is also common but slightly more common in males.
We spend less time on the toilet as we age.
Around 1 in 6 of us have IBS.
We fart an average of eight times a day.
Effect of gender on prevalence of irritable bowel syndrome in the community: systematic review and meta-analysis. The American Journal of Gastroenterology. (2012). https://pubmed.ncbi.nlm.nih.gov/22613905/
Sex-gender differences in irritable bowel syndrome. Journal of Neurogastroenterology and Motility. (2018). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6175559/