King Louis XIV

 Poor King Louis XIV developed an anal fistula in the late 1600s.

His doctor , a chap named Charles-Françoise Felix, spent months conducting experiments on peasants in a charity hospital.

I'm not sure how keen they were to volunteer, and it's likely some died of infection, but Felix remained determined not to make a fist of his fistula research.

Eventually, he'd learned enough to construct enough of his fistula bursting implement with which he took a run at the royal rump .

The operation was a success.

However, because anything Louis did became fashionable, his courtiers demanded the treatment for themselves.

A perplexed Felix sensibly declined to puncture any more anal glands than was strictly necessary.

Source- Greg Jenner, "Ask a historian ".