It's a case that brings new meaning to the phrase 'getting on the piss'.
A woman in the United States suffering cirrhosis of the liver was told by her doctors to get treatment for alcoholism - but she insisted she never drank.
It turned out her bladder was producing its own alcohol, in what doctors are now calling the first recorded case of urinary auto-brewery syndrome.
The 61-year-old woman was on the waiting list for a liver transplant, suffering cirrhosis and diabetes.
Urine tests showed the presence of alcohol, but she swore to be teetotal.
Further testing found while ethanol was present in her wees, ethyl glucuronide and ethyl sulfate weren't - and should have been if she'd been drinking. She also didn't appear drunk at any time.
So the doctors did an experiment, trying to ferment sugar using yeast from the bladder - and it worked.
"They were able to conclude that the patient had a novel form of auto-brewery syndrome and not alcohol use disorder," the American College of Physicians said in a statement.
Previous cases of auto-brewery syndrome have been recorded in the digestive system. In 2015 a British man complained to the BBC every time he ate chips or other carb-heavy food, he got drunk and would wake up hungover.
The latest case was detailed in the journal Annals of Internal Medicine on Tuesday (NZ time).