Researchers in Minnesota unexpectedly found cloudy white fluid inside several colonoscopes and gastroscopes after they had been disinfected and deemed ready for use on the next patient.
Further analysis revealed that the fluid contained simethicone, the main ingredient in over-the-counter anti-gas medications available at grocery stores and pharmacies. Doctors regularly inject the liquid drops into gastrointestinal scopes during colonoscopies and other procedures to reduce bubbles inside the body that can impede visibility.
However, that routine practice may be helping bacteria grow inside a wide variety of scopes and making the bacteria harder to remove. The authors of the study, published in August in the American Journal of Infection Control, recommend that hospitals and doctors minimize the use of these products pending further research into their effect on patient safety.
No infections have been linked to the drops thus far. The study only suggests that they could heighten the risk of contamination. “Finding residual fluid in scopes that should be dry would be troubling alone,” says Cori Ofstead, the study’s lead author. “The finding of fluid containing simethicone suggests we have more serious problems. It could explain why we are having more trouble getting these scopes clean.”
Infant gas relief drops, which are available over the counter, contain sugars and thickeners to make the liquid solutions more palatable for babies, the researchers say. Ofstead said those ingredients “could provide the perfect habitat for the growth of bacteria” inside scopes.
The liquid drops contain silicone, which doesn’t dissolve in water and can’t be removed using detergents or disinfectants. The researchers said that silicone could add an impenetrable coating to blood, tissue and other organic material trapped inside scopes. It can also foster the growth of biofilm, a slimy material that protects bacteria and other microbes from being removed during cleaning.
Ofstead, an epidemiologist and chief executive of the …