We go to the smallest room to do our most private and – literally – pressing business. And we don’t talk about the outcome – except, perhaps, with a doctor, if something seems amiss.
Our stools are an important indicator of our health. Dr Heiner Wedemeyer, director of the Department of Gastroenterology, Hepatology and Endocrinology at the Hanover Medical School (MHH) in Germany, explains what normal stool looks like and when you should consult a doctor.
What do our stools say about us?
Wedemeyer: For one thing, they’re an indication of what we’ve eaten as well as of illnesses. And we all have a distinctive stool microbiome – that is, a particular community of gut bacteria. It varies greatly from person to person, but is relatively constant in each individual and it even restores itself. If you’ve had a colonoscopy and completely emptied your colon, for example, in time the same community of bacteria will reassemble.
We gastroenterologists look at several things in regard to stool: its frequency, consistency, colour and smell. The amount can be telling too. All of these things can be influenced by food, but also by inflammation, infections, other illnesses or allergies.
As a doctor, I look at patients closely and work through everything systematically. What do their stools look like and are other symptoms present? What do they eat and what medications do they take? It’s usually detective work but often pays off because checking off these questions is, in many cases, of consequence for the diagnosis and therapy.
How many bowel movements a day are normal, and when should you be concerned?
Wedemeyer : From a long-term perspective, once or twice a day is good. Sometimes patients come to me and say, “I’ve got diarrhoea.” When I ask them how often they have to go to the toilet, they say, “Once a day.” I then tell them that technically this isn’t diarrhoea. The definition of diarrhoea is having to go to the toilet more than three times a day and stool that’s generally watery.
And it’s not a catastrophe if you don’t have to go to the toilet every day. Some people have a bowel movement once every three days for many years. That’s OK too. But if the intervals are longer, you should consult a doctor, because chronic constipation can be caused by illnesses.
What colour is healthy stool, and what can be a sign of illness?
Wedemeyer : Healthy stool is brown. It gets its characteristic colour from bile pigments in the intestines that are broken down by gut bacteria. If bile flow is disrupted by illness, such as a liver disorder, gallstones or a tumour, your stool becomes paler – it loses its colour.
Very dark stool may be due to blood, which can come from the stomach, for example. Certain bacterial infections can turn it green, and at the same time often give it an extremely foul odour.
And food can directly change stool’s colour, of course. If you eat a lot of carrots, for instance, your stool may look somewhat orange. If you eat a lot of meat, it tends to be darker. Eating large amounts of spinach can give it a greenish colour.
When is a doctor’s visit imperative?
Wedemeyer : If your stool is completely colourless, you must see a doctor. Full stop. White stool, very light in colour, perhaps in combination with a yellowing of the whites of your eyes – if you’ve got that, you should go to a doctor pronto and not delay.
And if your stool is black, so-called tarry stool, and you haven’t eaten, say, an enormous amount of blueberries, you should also see a doctor immediately. It can be a sign of serious bleeding, especially if it’s accompanied by lethargy, dizziness and a rapid pulse.
In the case of greenish or yellowish stools, on the other hand, you can wait two or three days so long as you don’t have severe diarrhoea or other signals. While stool colour is important, if something serious is behind it there are usually other symptoms as well, such as fever, yellowing of the whites of your eyes, pain, diarrhoea or weight loss.
How firm should your stool be?
Wedemeyer : It should be soft and solid. It may occasionally be loose or watery, but if this consistently happens you need to take a closer look: Is it only watery or is it really greasy? This can be due to your pancreas not functioning normally, for example. You may also have an infection or a food allergy.
On the other hand, chronic constipation and hard stools can be a sign of early-stage colon cancer. (DPA)