On Dec 14th 2013 I posted about how the colour of your urine says something about your health (spoiler alert: the lighter it is the better!). Just over three years later I posted something similar, this time about the colour of poop. Let’s just say that you don’t want black.

Perhaps it is the time of year but today I read an article about why poop is brown. However, this time it was in TheConversation. TheConversation is an incredibly good website. It was first produced in Australia in 2011 and is a non-profit media outlet. In the UK it is supported the UK government and a number of UK universities (including University of Leeds where I work) to generate journalistic content that people can trust – academic rigour with journalistic flair.

I have only published in TheConversation once. I was invited to write about the effect of light on colour. I am quite proud of the fact that my article is the fifth most read article of any produced from the University of Leeds. It has 190,225 reads which is approximately 190,220 more reads than most of my academic papers ever achieve. So it’s a great way to get stuff out and have an impact.

However, I was invited to submit the article and even then I went through quite a rigorous process where the editor who is assigned to your case asks for evidence for every claim you make. So it’s not easy to publish there. The upshot of all of this is that TheConversation can be trusted. One of the problems with the current world, imho, is that the freedom that the internet has given us – where anyone can put stuff out there and where the world is no longer controlled by a small number of publishers – needs to be balanced by the problem that anyone can put stuff out there. There is more nonsense written on the internet about colour than almost any other topic apart from, perhaps, COVID, vaccines and masks. I won’t comment about those topics because I know no more about them than you – possibly less. But if you want to read reliable information about anything, written in a clear and simple way by people who study that topic for a living, I cannot recommend TheConversation more highly.

However, back to the more important topic – colour of poop. The article is actually a response to a question that was received from a child in Maryland and is part of a series for children of all ages called Curious Kids.

The brown colour is produced by the bile pigment stercobilin – first isolated from faeces in 1932 – without which poop would probably be very pale, almost white. The presence of this particular pigment in water is sometimes used to detect faecal pollution levels in rivers. So now you know one more colorant; albeit a natural one.

There is a related article about poop and health on TheConversation if you are interested. To make the point about articles in TheConversation being written by people who know what they are writing about they note in their article:

Have you ever wondered what’s going on in your poop? Perhaps not. But this is precisely what we think about every day at the American Gut Project, the world’s largest microbiome citizen science effort, located at UC San Diego School of Medicine.