It’s one of the world’s great mysteries – why do some poos float while others sink?
Well, a group of scientists has taken a fresh look at a 50-year-old study to find the answer and think they have found some interesting information.
The research found that when poos that float are smushed-up, they sink to the bottom.
And that is because floating poos have a high gas content, so if a poo floats or sinks is down to the amount of gas.
Scientists have said that is why gut bacteria is so important. They hope their work will help people understand the link between gut health and gas.