funny colonoscopy stories

It's 1962. USAF Major Frank Borman (later commander of Apollo 8, the first human flight around the Moon) is taking the medical tests attending on his application to become an astronaut, and this includes a colonoscopy:

Mine revealed a polyp the size of a BB shot; they took it out and, although a biopsy showed it to be non-malignant, they insisted on my staying over for additional GI tests.
I got the usual barium enema, followed by a session with some kind of X-ray machine hooked up to a small screen. They laid me on one side and started looking at the feature presentation on the screen.
One doctor exclaimed, "My God, look at that!"
Another said in the tone of a hanging judge, "You've got a mass in your belly, Major - it's a tumor. Very serious. You'll have to go into surgery this afternoon."
"You're nuts!" I retorted. "There isn't a damned thing wrong with me."
The four internists clustered around the table clucked disaprovingly at this amateur diagnosis. "Take a look at what's on the screen," the principal voice of doom advised ominously.
I looked and broke into a cold sweat. Sure enough, there was a white mass in my intestines. They were still conferring over the telltale X ray when a radiologist, a Dr. Randall, happened to come in and immediately asked what all the fuss was about. A definite tumor, possibly malignant, he was told. He looked at the screen and shook his head.
"Turn him over," he ordered.
They did. The white mass disappeared. Randall stared unbelievingly at his colleagues, as if they were a quartet of medical students about to flunk out.
"You've been looking at a pool of barium," he murmured.

- Frank Borman, with Robert J. Serling, Countdown: An Autobiography (1988)