We've all experienced it.
Waking up after a night of drinking and immediately having to make a beeline for the bathroom.
It's well known that alcohol is a diuretic, which makes you produce more urine. But why does it affect our poos too?
Apparently, we have the ethanol in alcohol to thank for that.
According to gastroenterologist Dr Kathlynn Caguiat, "Alcohol can increase gut motility and it doesn't get broken down before it reaches the colon, where bacteria feast on these, resulting in bloating and diarrhoea."
As gut motility is increased, everything moves a lot quicker than usual, which means the colon has less time to absorb any water, resulting in watery stools and diarrhoea.
"The more concentrated the alcohol, the worse the reaction will be," Dr Urvish Shah, gastroenterologist, warns.
"Alcohol also increases the acid content in your stomach, which can easily irritate the lining and trigger stomach and digestive problems," Shah continues.
Malt liquor will apparently cause the worst post-booze bathroom runs, followed closely by beer.
To ease the toilet situation, try drinking wine or clear spirits instead - and always eat before you hit the booze.
So there you go! Hangover poo is a real thing.