There’s a common assumption men take longer than women to poo. People say so on Twitter, in memes, and elsewhere online. But is that right? What could explain it? And if some people are really taking longer, is that a problem?

As we sift through the evidence, it’s important to remember pooing may involve time spent sitting on the toilet and the defaecation process itself.

And there may be differences between men and women in these separate aspects of going to the toilet. But the evidence for these differences isn’t always as strong as we’d like.

Men may spend longer sitting on the toilet

Men do appear to spend more time sitting on the toilet. An online survey by a bathroom retailer suggested men spend up to 14 minutes a day compared with women, who spend almost eight minutes a day. But this survey doesn’t have the rigour of a well-designed scientific study.

Would there be any physiological reason to explain why men spend longer on the toilet? Well, the evidence actually suggests the opposite.

We know it takes longer for food to travel through the intestines in women than in men. Women are also more likely to suffer from constipation related to irritable bowel syndrome than men. So, you’d expect women to take longer to defaecate, from the start of the bowel motion to expulsion.

But this is not the case even if you take into account differences in fibre intake between men and women.

Instead, how long it takes someone to poo (the defaecation time) is heavily influenced by the mucus lining the large bowel. This mucus makes the bowel slippery and easier for the stools to be expelled. But there’s no evidence this mucus lining is different in men and women.

One thing we do know, however, is mammals from elephants to mice have a similar defaecation time, around 12 seconds.

For humans, it’s slightly longer, but still quick. In one study it took healthy adults an average two minutes when sitting, but only 51 seconds when squatting. Again, there were no differences in defaecation time between men and women, whether sitting or squatting.

If there’s no strong evidence one way or the other to explain any gender differences in how long it takes to poo, what’s going on? For that, we need to look at the total time spent on the toilet.

Why do people spend so long on the toilet?

What I call the “toilet sitting time” is the time of defaecation itself and the time allocated to other activities sitting on the toilet. For most people, the time spent just sitting, aside from defaecating, accounts for most of their time there.

So what are people doing? Mainly reading. And it seems men are more likely to read on the toilet than women.

For instance, a study of almost 500 adults in Israel found almost two-thirds (64%) of men regularly read on the toilet compared with 41% of women. The longer people spent on the toilet, the more likely they were to be reading. However, in the decade or more since this study was conducted, you’d expect adults would be more likely to be reading or playing games on their mobile phones rather than reading paper books.

People might also be sitting longer on the toilet for some temporary relief from the stresses of life.

One poll found 56% of people find sitting on the toilet relaxing, and 39% a good opportunity to have “some time alone”. Another online survey revealed one in six people reported going to the toilet for “peace and quiet”. Although these are not scientific studies, they offer useful insights into a social phenomenon.

Then there can be medical reasons for a prolonged defaecation time, and consequently a lengthier time sitting on the toilet.

An anal fissure (a tear or crack in the lining of the anus) can make defaecation a painful and lengthy process. These fissures are just as common in men as in women.

And obstructive defaecation, where people cannot empty the rectum properly, is a common cause of chronic constipation. This is more common in middle-aged women.

Are there any harms from spending too long on the loo?

In a Turkish study, spending more than five minutes on the toilet was associated with haemorrhoids and anal fissures. Another study from Italy noted the longer the time people spent on the toilet, the more severe their haemorrhoids.

One theory behind this is prolonged sitting increases pressure inside the abdomen. This leads to less blood flow into the veins of the rectum when passing a bowel motion, and ultimately to blood pooling in the vascular cushions of the anus. This makes haemorrhoids more likely to develop.

What can we do about this?

In addition to the usual advice about increasing the amount of fibre in your diet and ensuring you drink enough water, it would be sensible to limit the amount of time spent on the toilet.

Different researchers recommend a different upper limit. But I and others recommend the SEN approach:

• Six minute toilet sitting time maximum
• Enough fibre (eating more fruit and vegetables, and eating wholegrains)
• No straining during defaecation.

Article by Vincent Ho, Western Sydney University. Vincent Ho, Senior Lecturer and clinical academic gastroenterologist, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.