"My doctor tells me I should get a colonoscopy."

DEAR A.J.,
I’m about to turn 50, and my doctor tells me I should get a colonoscopy. Is this really necessary? It sounds highly unpleasant.—ERICA IN MARYLAND

Listen, I understand that a colonoscopy is a pain in the, um, neck. But yes. You really should get one. Science says so. And to make yourself feel better mid-probe: Just think about the medical practices of the past. They make colonoscopies look like a nice way to spend your Tuesday morning.

You’ve probably heard of snake oil? The original snake oil was a Chinese remedy for joint pain. But when it comes to animalistic cures, that was the least of it. In ancient Egypt, the cure for a toothache was to place a hot, freshly sliced mouse on your ivories. Which is crazy, because everyone knows that the proper medical use for a mouse is to fry it and eat it to cure whooping cough (at least that’s what many Brits thought in the 19th century).

The list goes on: Boiled cockroaches cured earaches, crushed cockroaches treated ulcers and cancer, and cow dung healed fractures. George Washington’s doctor swabbed the Founding Father’s throat with dried beetle paste to cure his cold.

And then there was trepanation. This is the official term for drilling a hole in your head. To repeat: a hole. In the head. Medical experts from various cultures—from the Neolithic period to Renaissance Europe and even the present day—thought perforation of the skull could help with migraines, epilepsy, and other ailments.

Early-20th-century American doctor John Brinkley had his own simple cure-all: surgically inserting a goat’s glands into the scrotum (for a man, obviously; for a woman, the glands went into the abdomen). This was supposed to help with everything from impotence to senility, flatulence to weak eyesight. Mostly, though, it just helped make Brinkley a multimillionaire.

Still, goat gonads are preferable to flat-out poison. The toxic metal mercury was a popular treatment for syphilis (Beethoven’s doctors gave him mercury ointment). It was also prescribed for toothaches, tuberculosis, and constipation. As a young politician, Abraham Lincoln took mercury-laced blue pills, which some historians speculate led to his mood disorders. And in the early 1900s, radioactive water was all the rage as a treatment for lethargy. You could also buy radioactive toothpastes if you wanted a truly glowing smile.

Throughout much of history, if your medicine man wasn’t killing you outright, he was being supremely creepy. Until the 20th century, European and American doctors would relieve women’s “hysteria” with a vaginal massage to “paroxysm.” In fact, the first electronic vibrator was designed in 1880 to relieve doctors of this manual labor.

The list of insane medical practices could fill a thousand prescription pads, but let’s instead end where we began—at the end. Although colonoscopies are new, medical rear entry is not. Consider one of the most popular cures of times past: the smoke enema. Here, a doctor would blow tobacco smoke into a hose and up the patient’s bottom. It was supposed to treat everything from stomachaches to cholera to drowning. It’s the origin of the phrase “I’m not just blowing smoke up your arse.” And kids, remember: It’s just not cool.

This story originally appeared in an issue of mental_floss magazine. Subscribe here.