A very fibre-heavy diet – the type eaten by many people in developing countries, and by some vegetarians in the UK – leads to much denser and bulkier poos. They are bigger movements that come out more easily. And there’s very less need to wipe as it is a much cleaner evacuation.
10 faeces facts
1. What is faeces?
Faeces (poo) is mostly water (about 70-75%).
2. Composition (other)
There are alot of bacteria in poo. The remaining 25-30% is bacterial biomass, fibre, dead and live cells, mucus, and other solid materials like cellulose from vegetables. The bacteria in poo can be either living or dead, and some of it comes from the intestines.
Lactobacillus johnsonii, a beneficial species of gut bacteria (Kathryn Cross, IFR)
In fact over 100 trillion bacteria reside in your gut, and many of them end up in your faeces.
3. Colour
The brown colour of faeces is due to bilirubin, a pigment found in bile.
But it can also be other colours. For example, pale grey or whitish poo could be a sign of liver disease or clogged bile ducts, while yellow poo could be caused by a parasitic infection or pancreatic cancer. Green poo could be caused by a gut infection like salmonella, giardia, or norovirus.
4. Weight
Poo is not as heavy as people think. The average adult human makes between 100 and 250 grams (3 to 8 ounces) of faeces per day. Thus means that in a year, a person excretes about 145 kg of poo.
5. Frequency – how often should I go to the toilet for a poo?
There is no ‘right’ number of bowel movements a person should have, and what’s normal for you can vary from day to day and week to week. A healthy frequency can range from three times a day to three times a week, but it depends on your normal pattern.
The average person poos about seven times a week.
But interestingly, how often people poo (within that 7x a week) is very variable – from person to person and even culture to culture. As we say, anywhere from three times a day to once every three days is normal. As long as you are in that range and feeling comfortable, you are normal.
Doctors can now perform stool transplants – taking the stool from a healthy person and transferring it to patients suffering from illnesses such as C. diff colitis. The ‘good bacteria’ found in healthy poo can fight off serious and potentially life-threatening infections.
6. Transit time
Food (that becomes poo) can take 72 hours to travel from the stomach through the colon
Though, on average, it takes 7 seconds for food to travel through the oesophagus to the stomach.
7. Gender difference
Men and women poo differently.
Because of anatomical differences, men and women’s GI tracts look and work a little differently. In fact, doctors that perform colonoscopies can correctly guess the patient’s gender without knowing it beforehand.
For a start, women have wider pelvises than men, as well as extra internal organs (such as the uterus and ovaries) in the region. As a result, their colons hang a bit lower than men’s, and are a bit longer – on average, by ten centimetres. Finally, men have more rigid abdominal walls that help push food through the GI tract more effectively.
Thus food takes longer to transit through most women, making them more prone to bloating. Men, on the other hand, are generally much more regular.
8. Geographical variation
People in different parts of the world have different poo. It might not be a huge surprise that different diets lead to different types of poo. The faeces of most people in the developing world are noticeably different from those of people eating a Western diet, mostly because the latter contains much less fibre.
Western-style stools, by contrast, are much softer, and the colon has to push harder to get them out.
9. Very smelly poo
This may be a sign of infection. Poo rarely smells ‘nice’. But particularly pungent stool is often a sign of infection. Terrible-smelling poo can indicate Giardia parasites, often ingested whilst swimming in untreated water in springs, rivers, or lakes.
10. What is the Bristol stool chart?
This chart below is used by doctors and nurses to describe the shape and consistency of poo. Seriously!
Constipation
- There is no agreed definition of constipation. But it is usually taken to mean a reduction in the frequency of pooing +/- difficulty passing (poo and/or farting).
- If you are constipated for more than 2 weeks you should see a doctor and be examined. You are likely to need a colonoscopy if it goes on for more than 4 weeks.
- Not passing any poo (or farts) is serious and you should see a doctor in 24-48 hours.
Finally .. bird ‘poo/wee’
Birds, unlike mammals, do not have separate exits for urine and feces. Both waste products are eliminated simultaneously through the cloaca. While mammals excrete nitrogenous wastes mostly in the form of urea, birds convert it to uric acid or guanine, which reduces water loss in comparison. Uric acid thus forms a white sticky paste. So the white part is actually bird wee; it is the dark centre that is the poo.
Summary
We have described 10 interesting facts about faeces (poo). We hope it has been helpful.
Other resources
Review article: Mawer, 2023
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