It's not exactly common, but we've all probably experienced the floating turd. So what exactly does it mean if your stool is not sinking?
“A floating stool is simply less dense than a sinking stool,” says gastroenterologist Neil Stollman. Doctors used to think this resulted from excess fat in the faeces, but one study in the New England Journal of Medicine suggests it’s actually extra air. Dr. Stollman says it could probably be either, though air is more likely.
Extra air in the stool could come from unabsorbed carbohydrates, like lactose or fibre, which ferment in the colon and release gas, says Dr. Stollman. This may be more likely to happen if you’re lactose intolerant or have just consumed a lot of dairy or fibre all at once. Sugary alcoholic drinks and artificial sweeteners can also make your poop gassier, says gastroenterologist Kenneth Brown.
And if your poop contains more air or gas than normal, it will make it lighter—thus more likely to float on top of the water than sink to the bottom of it, like denser turds do.
Still, it's possible that extra fat in your faeces can cause it to float, too. In this case, eating more fatty food than normal is likely the culprit, says Dr. Stollman. When your intestines can't absorb all that fat, it's excreted through your poop.
In rarer cases, fatty, floating stools—officially known as steatorrhea—can signal that your body is unable to digest and absorb nutrients, like fat, properly. This is called malabsorption.
If there are also drops of oil in the toilet, your pancreas might not be working properly to absorb the fat you eat, says Dr. Brown. And oil in the poop itself might mean the bacteria from your small intestine are growing outside it, breaking it down before you can.
Doctors can diagnose malabsorption through a faecal fat test, which literally measures the amount of fat excreted in your stool. If your floating poop is caused by malabsorption, you will probably have other signs as well, like frequent loose stool, extremely foul-smelling stools, abdominal cramps, and gas.
That said, in most cases, floating poop on its own probably doesn’t indicate any problem. “Very few people have consistent bowels,” says Dr. Stollman. Most changes are simply due to diet or medications. But if you notice a change for a month or more, talk to your doctor just to be safe.
This article originally appeared on Men's Health