A 63-year-old man in Missouri went in for a routine colonoscopy, only to give doctors an extremely rare find: a perfectly intact (albeit dead) fly.
"I've been doing this for over 20 years, so I've seen a lot of things," said the gastroenterologist, Dr. Matthew Bechtold, according to Yahoo! News. But "having such an intact fly like this is just unheard of."
How the fly found its way into the man's colon remains a mystery, as the patient says the only thing he'd consumed for at least 24 hours before the colonoscopy was clear liquids, as instructed by the doctors. Two days earlier he had eaten some pizza and lettuce, but did not see any flies around his food. And anyway, as Dr. Bechtold told The Independent via Science Alert, if the fly had entered through the mouth, enzymes and stomach acid would have "degraded" the insect before it made its way to the colon.
The only other possible way into the colon is the rectum, but that port of entry also seems unlikely. "If from the bottom, an opening must have been created long enough for the fly to fly undetected into the colon and somehow make its way to the middle part of the colon with no light in a very curvy, large intestine," Dr. Bechtold said.
The insect was found in the transverse colon — part of the colon situated below the liver that travels right to left.
What's remarkable, Bechtold said, is that the fly wasn't digested and that it didn't get flushed out during bowel prep for the colonoscopy, which involves consuming only clear liquids and taking laxatives a day before the procedure.
"It was the first time I've seen this big of an insect and this much intact of an insect," Bechtold said.
When doctors showed the patient pictures of the fly in his colon after the procedure, "He's like, huh, I must have eaten a fly," Bechtold said.
Images of the undigested fly can be found here in the American Joural of Gastroenterology.