Transplanting faecal matter from one person to another - the thought might turn your stomach, but it could be lifesaving.
Some doctors are using the procedure to repopulate the gut with healthy bacteria, which can become unbalanced in some diseases.
Dr Alisdair MacConnachie, who thinks he is the only UK doctor to carry out the procedure for Clostridium difficle infection, describes it as a proven treatment.
He says it should be used, but only as a treatment of last resort.
The logic is simple.
C. difficile infection is caused by antibiotics wiping out swathes of bacteria in the gut. It gives the surviving C. difficile bacteria room to explode in numbers and produce masses of toxins which lead to diarrhoea and can be fatal.
The first-choice solution, more antibiotics, does not always work and some patients develop recurrent infection.
The theory is that by adding more bacteria to the bowels, they will compete with C. difficile bacteria and control the infection.
Dr MacConnachie, from Gartnavel General Hospital in Glasgow, has performed just over 20 of the operations since he started in 2003.
"Ultimately all the patients I've treated, bar one, has got rid of their C. difficile," he said.