Contains Nonbinding Recommendations 
Mitigating the Risk of Cross- 
Contamination from Valves and 
Accessories Used for Irrigation 
Through Flexible Gastrointestinal 
Endoscopes 
Guidance for Industry and  
Food and Drug Administration Staff 
Document issued on November 29, 2016. 
This draft of this document was issued on January 20, 2015. 
For questions about this document, contact the Division of Reproductive, Gastro-Renal, and 
Urological Devices, 301-796-7030, and Shanil Haugen, Ph.D., at 301-796-0301, email at 
shanil.haugen@fda.hhs.gov. 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Devices and Radiological Health 
Office of Device Evaluation 
Division of Reproductive, Gastro-Renal, 
and Urological Devices 
  Contains Nonbinding Recommendations 
Preface 
Public Comment 
You may submit electronic comments and suggestions at any time for Agency consideration to 
http://www.regulations.gov. Submit written comments to the Division of Dockets Management, 
Food and Drug Administration, 5630 Fishers Lane, Room 1061, (HFA-305), Rockville, MD 
20852. Identify all comments with the docket number FDA-2014-D-2153. Comments may not be 
 
acted upon by the Agency until the document is next revised or updated.
Additional Copies 
Additional copies are available from the Internet. You may also send an e-mail request to 
CDRH-Guidance@fda.hhs.gov to receive a copy of the guidance. Please use the document 
number 1400054 to identify the guidance you are requesting. 
  Contains Nonbinding Recommendations 
Table of Contents 
I.  Introduction ...............................................................................................................................1
II.  Definitions.................................................................................................................................2
III. Irrigation Channels....................................................................................................................4
A.  Air / Water Channel.............................................................................................................5
B.  Auxiliary Water / Forward Water Jet Channel....................................................................5
C.  Instrument / Working / Biopsy Channel..............................................................................5
IV. Mitigation of Cross-Contamination Risk ..................................................................................6
A.  Device Design ......................................................................................................................6
(1)  Prevention of Backflow to the Proximal Irrigation System.........................................6
(2)  Reprocessing or Disposal of the Distal Irrigation System ............................................6
(3)  Reprocessing or Disposal of the Proximal Irrigation System.......................................7
B.  Labeling...............................................................................................................................7
  Contains Nonbinding Recommendations 
Mitigating the Risk of Cross- 
Contamination from Valves and 
Accessories Used for Irrigation 
Through Flexible Gastrointestinal 
Endoscopes 
Guidance for Industry and  
Food and Drug Administration Staff
 
This guidance represents the current thinking of the Food and Drug Administration (FDA 
or Agency) on this topic.  It does not establish any rights for any person and is not binding 
on FDA or the public.  You can use an alternative approach if it satisfies the requirements 
of the applicable statutes and regulations.  To discuss an alternative approach, contact the 
FDA staff or Office responsible for this guidance as listed on the title page. 
I.  Introduction 
The objectives of this guidance document are to: 1) highlight the cross-contamination risk 
associated with specific types of irrigation valves and accessories when used with flexible 
gastrointestinal endoscopes; 2) clarify terminology used to describe these devices; and 3) outline 
strategies to mitigate the risk of cross-contamination between patients. Flexible gastrointestinal 
endoscopes and accessories (including valves and other devices used for irrigation) are Class II 
devices, as described in 21 CFR 876.1500. FDA uses product codes to identify devices that 
supply endoscopic irrigation, the most common being FDF (colonoscope and accessories, 
flexible/rigid), FDS (gastroscope and accessories, flexible/rigid), and OCX (endoscopic 
irrigation/suction system). These irrigation devices may be submitted to FDA in premarket 
notification (510(k)) applications as part of a flexible gastrointestinal endoscope system or 
separately as accessories to flexible gastrointestinal endoscopes. 
During colonoscopy or esophagogastroduodenoscopy (EGD), clinicians often use a water bottle 
to supply irrigation for the procedure. Clinicians typically use a single water bottle for multiple 
patients without reprocessing the water bottle between patients. This practice raises the risk of 
cross-contamination between patients, because the water bottle and associated tubing/connectors 
1  Contains Nonbinding Recommendations 
can become contaminated with blood,1 stool,2 or other patient fluids3 that travel back through the 
endoscope channels and tubing (a phenomenon hereafter referred to as backflow, see Figure 
1). FDA has received reports of backflow from irrigation channels into the water bottle and 
tubing when the irrigation channel did not have a backflow-prevention mechanism in place.  
This guidance outlines the recommended mitigation strategies to reduce the risk of cross-
contamination from connectors and irrigation accessories, including device design and 
appropriate labeling. The recommendations regarding the device design are limited to irrigation 
systems for flexible gastrointestinal endoscopy, because irrigation systems for other devices, 
such as arthroscopes, may require different risk mitigation strategies due to the need to 
aseptically handle those irrigation systems.  
For the current edition of the FDA-recognized standard(s) referenced in this document, see the 
FDA Recognized Consensus Standards Database Web site at 
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfStandards/search.cfm.  
FDAs guidance documents, including this guidance, do not establish legally enforceable 
responsibilities. Instead, guidances describe the Agency's current thinking on a topic and should 
be viewed only as recommendations, unless specific regulatory or statutory requirements are 
cited. The use of the word should in Agency guidances means that something is suggested or 
recommended, but not required.  
II.  Definitions 
FDA provides the following definitions for terms used to describe components of flexible 
gastrointestinal endoscopes and accessories.  We provide additional explanations for these terms 
in Figure 1.  To help ensure consistency in the use and premarket review of these devices, FDA 
recommends that device manufacturers use the terms and definitions described below in both 
their labeling and 510(k)s. 
FDA is defining both terms single-use device and disposable to refer to a device that is used 
on a single patient during a single procedure and then discarded.  A single procedure performed 
on one patient, hereafter referred to as a patient use, may include multiple insertions of an 
endoscope into the patient. 
                                                           
1 For a description of blood traveling back towards the water bottle, please see Report No. 09-01784-146 issued on 
June 16, 2009 by the Department of Veterans Affairs Office of Inspector General.  The report is titled Healthcare 
Inspection: Use and Reprocessing of Flexible Fiberoptic Endoscopes at VA Medical Facilities. 
(www.va.gov/oig/54/reports/VAOIG-09-01784-146.pdf).
2 For reports of stool traveling back towards the water bottle, please see these descriptions of two different events 
submitted to the FDA MAUDE Database:  
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/Detail.CFM?MDRFOI__ID=964104 and 
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/Detail.CFM?MDRFOI__ID=1474183 
3 For reports of unspecified patient fluids traveling back towards the water bottle, please see these descriptions of 
two different events submitted to the FDA MAUDE Database: 
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/Detail.CFM?MDRFOI__ID=2401789 and 
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/Detail.CFM?MDRFOI__ID=3229842
2  Contains Nonbinding Recommendations 
 24 Hour Use: The use of a device within a single 24-hour period with no reprocessing 
between patient uses. A device labeled 24 Hour Use implies multi-patient use. 
 Backflow-Prevention Valve: The valve that is intended to prevent the proximal irrigation 
system from being contaminated by backflow of fluids from the patient (see Figure 1).  
When multiple valves are present in the irrigation system, the backflow-prevention valve is 
the one closest to the patient.  When used in the auxiliary-water / forward-water-jet channel, 
this valve is frequently referred to as a one-way valve.  
 Consumable: A device that is intended to be discarded or replaced after use, with no 
reprocessing. Consumable devices include all single-use devices (see definition below) and 
the subset of 24-hour multi-patient use devices that are discarded after use. 
 Cross-contamination: The transfer of potentially harmful substances or disease-causing 
microorganisms from one patient to another patient. 
 Irrigation System: All devices and device components between the patient and the water 
bottle (including the bottle) that convey or contact water used for irrigation. The irrigation 
system may be subdivided into the Distal Irrigation System and Proximal Irrigation System: 
o  Distal Irrigation System:  All components of the irrigation system between the 
patient and the backflow-prevention valve, including the backflow-prevention 
valve (e.g., endoscope, distal tubes/accessories, etc.). 
o  Proximal Irrigation System: All components of the irrigation system between the 
water bottle and the backflow-prevention valve, excluding the backflow-
prevention valve (e.g., water bottle, water bottle cap, proximal tubes/accessories, 
etc.). 
 Multiple Patient Use (Multi-Patient Use) Device: A device that is intended to be used on 
multiple patients, either with reprocessing (for reusable devices) between patient uses or 
without reprocessing (for consumable devices) between patient uses. 
 Reprocessing: Validated processes used to render a medical device fit for a subsequent 
single use after it has been previously used or contaminated. These processes are designed to 
remove soil and contaminants by cleaning and to inactivate microorganisms by disinfection 
or sterilization.  For guidance regarding reprocessing of reusable medical devices, please see 
Reprocessing Medical Devices in Health Care Settings:  Validation Methods and Labeling 
(http://www.fda.gov/ucm/groups/fdagov-public/@fdagov-meddev-
gen/documents/document/ucm253010.pdf).  
 Reusable Medical Device: A device intended for repeated use, either on the same or 
different patients, with appropriate cleaning and other reprocessing between uses. 
 Single-Use Device (SUD): A single-use device, also referred to as a disposable device, is 
intended for use on one patient during a single procedure. It is not intended to be 
3  Contains Nonbinding Recommendations 
reprocessed (cleaned, disinfected/sterilized) and used on another patient.  For guidance 
regarding the labeling of single-use devices, please see Labeling Recommendations for 
Single-Use Devices Reprocessed by Third Parties and Hospitals 
(http://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceD
ocuments/ucm071069.pdf). 
Figure 1.  Illustration of critical terms defined in this guidance document. 
A backflow-prevention valve divides the irrigation system into distal and proximal components.  
The backflow-prevention valve is designed to prevent backflow of contaminated fluid (colored 
red here) from the patient into the proximal irrigation system so that the water bottle and 
proximal tubes/accessories may be used safely for multiple patients.  
III.  Irrigation Channels 
Channels used for irrigation are a potential source of contamination of the proximal irrigation 
system during the use of flexible gastrointestinal endoscopes.  These channels include: 
  Air / Water Channel 
  Auxiliary Water / Forward Water Jet Channel 
  Instrument / Working / Biopsy Channel 
4  Contains Nonbinding Recommendations 
A. Air / Water Channel 
An Air / Water Channel is present on most flexible gastrointestinal endoscopes. The water in this 
channel is directed towards the endoscope lens to wash debris from the lens. The backflow-
prevention valve in this channel is called the air/water valve or the air/water button. This 
backflow-prevention valve is located on the endoscope control handle, and should be labeled for 
reprocessing or replacement after every patient use because of the potential for contamination of 
the valve. 
B. Auxiliary Water / Forward Water Jet Channel 
An Auxiliary Water / Forward Water Jet Channel is present on a subset of flexible 
gastrointestinal endoscopes. The auxiliary water inlet is located on either the control handle or on 
the light guide connector. The water in this channel is forward-directing and is used to wash the 
gastrointestinal mucosa. The channel diameter is often wider than the diameter of the air/water 
channel, resulting in a powerful stream of water. For most endoscopes, the backflow-prevention 
valve is located outside of the endoscope body and may be part of the endoscope irrigation 
connector, or may be located within tubing that is attached to the water bottle.  
FDA has received reports that, in the absence of a backflow-prevention valve, patient fluids such 
as blood and stool can travel back through the auxiliary water channel and into the auxiliary 
water inlet and other parts of the irrigation system. Therefore, the length and narrow diameters of 
channels in gastrointestinal endoscopes alone may not be sufficient to prevent contamination of 
the irrigation system. Although FDA has not yet received reports of infection that can be 
attributed to backflow, the risk of cross-contamination should be mitigated by following the 
measures recommended below in Section IV.  
For auxiliary water channels with external valves, any device that is directly connected to the 
auxiliary water inlet (up to and including the backflow-prevention valve in the fluid pathway) 
should be considered part of the distal irrigation system and thus contaminated, and should be 
reprocessed or replaced after every patient use. For those endoscopes with an internal backflow-
prevention valve in the auxiliary water channel, the backflow-prevention valve should be labeled 
for reprocessing or replacement after every patient use. 
C. Instrument / Working / Biopsy Channel 
An Instrument / Working / Biopsy Channel is present on most flexible gastrointestinal 
endoscopes. The primary purpose of this channel is to allow instrument access through the 
endoscope; however, specialized connectors allow irrigation through this channel. The channel 
diameter is wide compared to other channels; therefore, irrigation through this channel has the 
potential to provide a powerful stream of water that can be used to wash the gastrointestinal 
mucosa. Any device or device component that is directly connected to the biopsy channel during 
an endoscopic procedure should be considered contaminated. As such, those devices should be 
labeled for reprocessing or replacement after every patient use. 
5  Contains Nonbinding Recommendations 
IV.  Mitigation of Cross-Contamination Risk 
The risk of cross-contamination from endoscope connectors during the use of flexible 
gastrointestinal endoscopes can be mitigated by a combination of device design, labeling, and 
proper device handling, as described below.  If the irrigation system does not include a 
backflow-prevention valve or other feature demonstrated to prevent backflow of contaminated 
fluids into the proximal irrigation system, then all components of the irrigation system should be 
reprocessed or discarded after being used during a procedure in one patient and before starting 
one in the next patient. 
A. Device Design 
(1)  Prevention of Backflow to the Proximal Irrigation System 
When irrigating through flexible gastrointestinal endoscopes, FDA recommends there be at least 
one device component within the irrigation system that has a backflow-prevention valve or other 
feature to prevent the backflow of fluids contaminated with microorganisms into the proximal 
irrigation system.  FDA recommends this backflow-prevention valve or other feature be tested 
with quantitative chemical and/or microbiological assays to demonstrate prevention of the 
backward flow of fluids under simulated use conditions.  
Performance testing of the device system incorporating backflow-prevention valves or other 
features for reducing the risk of cross-contamination between patients should utilize worst case 
conditions, including worst case backpressure, pressure cycling to simulate periodic changes in 
fluid pressure and flow, duration, and concentration of chemical and/or microbiological markers. 
The test protocol should identify relevant conditions including pressures, fluid volumes and flow 
conditions, type and purpose of connections within the flow path, tubing lengths, and time of 
relevant procedures that may influence backflow of fluid into the system. The test report should 
include relevant descriptive information on the system, including a description of the backflow-
prevention valve function and its critical operational characteristics such as cracking pressure 
and maximum back pressure, identification of the potential for regurgitation on valve closing, 
and the volume of fluid that may backflow upon regurgitation from back pressure. In addition, 
the test method should include appropriate positive and negative controls and be of sufficient 
sensitivity for the study objectives.   
(2)  Reprocessing or Disposal of the Distal Irrigation System  
Any device component in the distal irrigation system should be designed to be either reprocessed 
or discarded at the conclusion of a procedure in one patient and before starting one in the next 
patient.  
a.  Reprocessing Reusable Devices 
Reusable devices should be designed to withstand multiple cleanings and high-level disinfection 
or sterilization cycles. Manufacturers should validate their reprocessing instructions as 
recommended in the FDA guidance document entitled Reprocessing Medical Devices in Health 
Care Settings:  Validation Methods and Labeling (http://www.fda.gov/ucm/groups/fdagov-
6  Contains Nonbinding Recommendations 
public/@fdagov-meddev-gen/documents/document/ucm253010.pdf) and inform users that the 
reusable device should be reprocessed after every patient use. 
b.  Disposal of Consumable Devices 
Consumable devices in the distal irrigation system should be discarded or replaced after every 
patient use. To mitigate the risk of cross-contamination, you should not use devices in the distal 
irrigation system with multiple patients unless you reprocess the devices between patients.  
Currently, there are no accepted scientific methods to determine whether any amount of patient 
material can be unintentionally transferred from one patient to another patient without harm.  
Therefore, FDA does not recommend using 24-hour multi-patient use connectors in the distal 
irrigation system unless these connectors are reprocessed between patients. 
(3)  Reprocessing or Disposal of the Proximal Irrigation System  
Manufacturers may wish to indicate the use of proximal irrigation systems with a backflow-
prevention valve and for use in multiple patients over a certain time period (e.g., 24 hours or 
less), and then to be reprocessed or discarded.  FDA recommends device manufacturers provide 
performance data to support use in multiple patients and over the proposed time frame to 
demonstrate that the backflow-prevention valve or other feature in the distal irrigation system 
provides adequate mitigation against the risk of cross-contamination between patients. 
B. Labeling 
Labeling should be clear and specific regarding the proper use of the device. We recommend that 
terminology be consistent with the definitions provided in Section II of this guidance document. 
Instructions for use should address the following points: 
1.  Clear instructions for installing irrigation devices, including valves, connectors, and 
tubing, to the irrigation system of the endoscope; 
2.  Identification of the channel/inlet to which each device component connects; 
3.  Identification of compatible endoscopes and accessories (or criteria to determine 
compatibility); 
4.  Clear identification of the device or component that includes a backflow-prevention valve 
or other backflow prevention feature; 
5.  Identification of each device or component that is part of the proximal irrigation system 
or the distal irrigation system; and 
6.  Identification of the device as consumable or reusable. 
a.  Consumable Device 
i.  You should identify the device as a single-use device or a 24-hour 
multi-patient use device.  [Note that 24-hour multi-patient use devices 
should not be labeled single-use or disposable.] 
ii.  Consumable devices should not include reprocessing instructions. 
iii.  Labeling should include disposal instructions. 
7  Contains Nonbinding Recommendations 
iv.  For single-use devices, labeling  should specify that the device should be 
discarded after being used on one patient and should not be used on 
multiple patients. 
v.  For 24-hour multi-patient use devices, labeling should recommend a 
maximum number of patient uses as well as a maximum duration of use, 
up to 24 hours, prior to discarding the device. 
b.  Reusable Device  
i.  You should identify the device as reusable or reusable, after 24-hour 
multi-patient use.  
ii.  The validated reprocessing instructions should indicate whether the device 
is reprocessed after every patient use or after 24-hour multi-patient use. 
Reprocessing instructions should be consistent with the recommendations 
described in the FDA guidance document entitled Reprocessing Medical 
Devices in Health Care Settings:  Validation Methods and Labeling.  We 
recommend you refer to the current version of ANSI/AAMI ST91: 
Flexible and semi-rigid endoscope processing in health care facilities, for 
consensus recommendations regarding the reprocessing of flexible 
endoscopes and accessories.  
iii.  For 24-hour multi-patient use devices, labeling should recommend a 
maximum number of patient uses as well as a maximum duration of use, 
up to 24 hours, prior to reprocessing the device.   
Table 1 describes the recommended disposal/reprocessing actions for devices in the proximal 
and distal irrigation system labeled as consumable or reusable. The table describes the minimum 
recommended action that should be implemented to minimize risk, assuming that the irrigation 
system includes a backflow-prevention valve and performance data as described above has been 
provided. Reprocessing or replacing the entire irrigation system at the conclusion of the 
procedure in each patient is also acceptable and is recommended if the irrigation system does not 
include a backflow-prevention valve or other backflow-prevention feature.  
Table 1.  Irrigation Systems with a Backflow-Prevention Valve:  Recommended Labeling 
and Actions for System Components 
Frequency of  Labeling and Action for  Labeling and Action for 
Device 
Action  Consumable Device  Reusable Device 
Label as single-use device  Label as reusable device 
Distal 
After every 
Irrigation 
patient use 
Discard  Reprocess 
System 
After 24 hours  Label as 24-hour multi- Label as reusable, after 24-
patient use device  hour multi-patient use 
Proximal 
 (reprocessing 
Irrigation 
not necessary     
system 
between  Discard  Reprocess 
patient uses) 
8  Contains Nonbinding Recommendations 
Manufacturers of flexible gastrointestinal endoscopes and accessories (including valves and 
other devices used for irrigation) must establish and maintain procedures for validating the 
design of their device, which shall ensure that the device conforms to defined user needs and 
intended uses (21 CFR 820.30(g)). FDA interprets this to require manufacturers to validate the 
design, including instructions for use and associated claims, of such devices to ensure that the 
device can be safely and effectively used as intended. This data should be kept and maintained at 
the manufacturers facility. The data should be made available for review at the request of FDA 
or made available during an FDA inspection. 
9