the recommended instructions and device design for the ERBEFLO port connector do not adequately mitigate the risks of cross-contamination for endoscopy patients. This is because the connector, tubing, and/or water bottle can become contaminated with blood, stool, or other fluids from previous patients that travel back through the endoscope channels into the connector and tubing.
Endoscope connectors that are labeled for use with multiple patients over the course of 24 hours without reprocessing are known as 24-hour multi-patient use endoscope connectors. To date, the FDA has not received acceptable testing to demonstrate the safe use of these products, and recommends against their useTo mitigate the risk of cross-contamination and possible infection between patients, the FDA recommends the use of connectors with features that prevent patient fluids from flowing backwards into the endoscope (backflow prevention features). These connectors may be either single-use connectors that are discarded after each patient, or reusable connectors that are reprocessed according to their instructions for use prior to each patient.

https://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm604940.htm