Doctors are trying to figure out how a fully intact fly found during a colonoscopy got into a Missouri patient’s intestines.
A 63-year-old patient from Missouri underwent a routine colonoscopy, a screening test for colorectal cancer recommended for anyone over the age of 45.
The test revealed moderate pancolonic diverticulosis, five polyps that were removed during the procedure, and a mysterious finding — a fully intact fly in the transverse colon in the large intestine, according to the American Journal of Gastroenterology. The fly was not moving on its own or with manipulation of the scope.
The patient said he had no idea how the fly got into his body and showed no symptoms of having a live insect in his bowel.
A day prior to the procedure, he only consumed clear liquids, as recommended in the colonoscopy preparation instructions. The patient reported eating pizza and lettuce two days before the colonoscopy but did not recall a fly in his food.
Matthew Bechtold, the chief of Gastroenterology at the University of Missouri, told The Independent that the doctors are unsure how the fly made its way to the patient’s intestines.
The insect has unlikely entered through the patient’s mouth, as upper digestive enzymes and stomach acid would have degraded it. Reaching the middle part of the dark and very curvy large intestine from the bottom is also not very plausible.
The study suggests there have been rare cases where insects have remained intact throughout their journey into the digestive system.
Some cases can be explained by intestinal myiasis or infestation with fly larvae, which feed on dead or living tissue or ingested food, according to the Centers for Disease Control and Prevention.
Intestinal myiasis occurs when a person ingests fly eggs or larvae previously deposited in food. While some infested people show no symptoms, it may cause abdominal pain, vomiting, and diarrhea in others.
Besides the intestine, myiasis can occur in other anatomic sites, such as skin, eye, ear, and wounds.
The study concludes, “This case represents a very rare colonoscopic finding and mystery on how the intact fly found its way to the transverse colon.”
Do I need a colonoscopy?
While colonoscopies rarely find flies buzzing in the intestines, the screening test can detect irritated and swollen tissue, ulcers, polyps, and colorectal cancer, according to the National Institute of Diabetes and Digestive and Kidney Diseases.
A colonoscopy is performed with a flexible tube with a camera on one end, called a colonoscope. The doctor can find and remove most polyps and some cancers during the procedure.
Patients experiencing the following symptoms may need to undergo a colonoscopy:
- Bleeding from anus
- Changes in bowel movements, such as diarrhea
- Pain in the abdomen
- Unexplained weight loss
Routine colonoscopies are recommended for people 45 and older and those at a higher risk of developing colorectal cancer. The risk factors for developing colorectal cancer include:
- Being Black
- Having a personal or family history of colorectal cancer
- Having a personal history of ovarian cancer, polyps, or inflammatory bowel disease
- Having Lynch syndrome, a genetic disorder increasing the risk of colorectal cancer
- Being obese, smoking, or drinking alcohol
Colorectal cancer rarely shows symptoms before it has grown or spread. Therefore, regular screening is crucial to detect the disease at its early stage.
- The American Journal of Gastroenterology. To Be a Fly on the Wall: A Mysterious Finding on Colonoscopy.
- CDC. What Should I Know About Screening?
- CDC. Intestinal Myiasis -- Washington.
- NIDDK. Colonoscopy.