It's one of the most taboo subjects there is to discuss.
But one scientist has hauled poo in the limelight - and now everyone's talking about it.
Giulia Enders, a German microbiologist, claims that people in Western countries are emptying their bowels in totally the wrong way - and instead of sitting on the loo, we should be squatting.
Her book, Charming Bowels, which has topped the charts in her native country for several weeks, explores a number of gut health issues, from constipation to bacteria.
The overall message is that the gastrointestinal tract is 'the brain's most important adviser', affecting everything from mental to digestive health.
But there are also practical gems, such as how to poo properly.
Sitting is in fact all wrong, and actually prolongs the process, explains Ms Enders, who is studying in Frankfurt for her medical doctorate in microbiology.
It may also explain why haemorrhoids (piles) and painful bowel diseases such as diverticulitis are more common in the West than in Asia, she adds.
She said: '1.2 billion people around the world who squat have almost no incidence of diverticulitis and fewer problems with piles.
'We in the West, on the other hand, squeeze our gut tissue until it comes out of our bottoms.'
Instead, the correct way is to squat.
Although you can climb on your toilet seat and squat, the kink can also be ironed out by sitting with your feet on a little stool and leaning forward.
Ms Enders adds there is a wealth of research that shows squatting is a more effective way to evacuate the bowels.
This is because the closure mechanism of the gut is not designed to 'open the hatch completely' when we’re sitting down or standing up: it’s like a kinked hose.
She explained: 'When you sit or stand, there's a muscle that goes around the end of the colon and it pulls, so there's a curve.
'When we're in a squatting position, and have a little stool in front of the toilet, then the angle is even and straight, so there's less pressure needed.'
'Squatting is far more natural and puts less pressure on our bottoms.'
Some experts claim we all used to squat - until the middle of the 19th century - and the demise of squatting is to blame for soaring rates of bowel and digestive issues.
As US-based doctor Joseph Mercola writes on his webpage: 'Infants instinctively squat to defecate, as does the majority of the world's population.
'But somehow the West was convinced that sitting is more civilized.'