BSG Guidance on Decontamination of Equipment for Gastrointestinal Endoscopy

The Report of a Working Party of the BSG Endoscopy Committee


1. Decontamination of endoscopes should be undertaken by staff trained and educated in the procedures within dedicated and well-designed rooms. There should be one- way flow of endoscopes between dirty returns and clean dispatch areas to prevent cross contamination. Best practice is that there should be physical separation of dirty and clean procedures and areas, each with its own detailed procedures. The washroom area, if separated dirty and clean rooms are used, should have a negative pressure in comparison to the clean side. See Health Technical Memorandum (HTM) 01-06 part B. If a single room procedure is used, the room must be well designed to ensure a good and safe flow is well managed. Units should be moving away from single-room facilities and all new designs should have split rooms with clearly segregated clean and dirty areas.

2. Staff training should be implemented using a competency framework and should be documented and revalidated annually. Training should include an awareness of the channel configuration of all endoscopes, manual cleaning procedures and of the endoscope washer disinfectors (EWD) and available irrigation adaptors, and any post cleaning processes (e.g. controlled environment storage cabinets [CESCs]) or portable storage systems, such as vacuum packing, that may be in use. See HTM 01-06 part D. These systems must be checked on a regular basis and validated by the manufacturer.

3. Traditionally, it has been recommended that before the start of each list, each endoscope to be used should undergo a full reprocessing cycle unless last used and decontaminated within the preceding 3 hours. Where appropriate quality assurance data are available, the use of CESCs or portable storage systems may obviate the need for repeat endoscope reprocessing at the start of each list.

4. Thorough manual cleaning with a CE marked detergent that is compatible with the disinfectant, including the brushing and flushing of all accessible endoscope channels, must be undertaken before automated endoscope disinfection within an EWD. This routine must be undertaken during lists, between patients and after each patient examination.

5. Units should no longer be using aldehyde- and alcohol-based disinfectants because of their fixative properties, which in theory could anchor prion and other proteins within endoscope channels. Units should employ single-use disinfectants within purpose-designed washer disinfectors.

6. All detergents and disinfectants must be compatible with the EWD and endoscope and used at the correct temperatures and concentrations in accordance with the detergent and disinfectant manufacturers’ instructions. Machine testing should include the efficacy and reproducibility of the detergent and disinfectant dosing system, in accordance with the EWD manufacturer’s instructions.

7. It is important to ensure that both the endoscope and EWD manufacturers have type- tested the chosen detergents and disinfectants that are compatible for use with their products.

8. It is essential that all reprocessing stages are included and documented after every use of the endoscope, and that none is omitted. It is also essential that all channels of all endoscopes are reprocessed after every use of the endoscope, even those that were not used during the preceding patient procedure.

9. EWDs should be used to wash and disinfect all endoscopes following manual cleaning. Manual disinfection alone is unacceptable. Some endoscopes may need to be sterilised depending upon their intended use, with a sterilisation process that is compatible with the endoscope. Users must ensure that the correct adaptors are available for all endoscopes to ensure irrigation of all channels. See HTM 01-06 part E.

10. Filtered air should be used as part of the drying process for each endoscope at the end of each EWD cycle. CESCs are recommended to store cleaned endoscopes. These are designed to deliver high-efficiency particulate filtered air (HEPA) to the internal channels at the appropriate temperature and flow rate. Due to its fixative properties, the use of alcohol to assist in drying endoscopes is no longer recommended.

11. Water used in an EWD should be free from particulate and chemical contamination and micro-organisms. This can be achieved either by using water purification systems, which can be a combination of high-level filtration and additional disinfection methods (e.g ultraviolet light), or by using a reverse osmosis plant. In-line water softeners may be needed if the local supply delivers hard water. The final rinse water should be sampled from the EWD and tested weekly for its microbiological quality in accordance with International Organization for Standardization ISO 15883- 4:2018 or HTM 01-06 part E. Trending of results is advised to identify any potential problems.

12. Hospitals undertaking endoscopy outside normal working hours will need to ensure that any remote facility is able to accept endoscopes for reprocessing on weekend days and public holidays. All endoscopes should be reprocessed as soon as possible following use, but routinely within 3 hours. Endoscope drying and storage facilities need to be present both in the endoscopy unit and in the remote facility. Any processed endoscope that remains outside such storage facilities or are unwrapped will need to be used within three hours of reprocessing, which must include (i) the transportation time between reprocessing or leaving storage at the remote site and the return to storage at the endoscopy unit PLUS (ii) the time between storage and use in the next patient in the unit itself. An electronic tracking and traceability system is mandatory for units relying on a remote decontamination facility.

13. A record should be kept of the serial number of each endoscope used on each patient. This log should include any loan endoscopes. This is important for any future contact tracing when possible endoscopic transmission of disease is being investigated. Details of each decontamination step, including the operator performing the bedside clean, leak test and manual clean, the EWD and the cycle details, including cycle number, used in decontaminating that endoscope should also be kept. This log should also include loan endoscopes.

14. The agent of variant Creutzfeldt-Jakob disease (vCJD) is believed to be resistant to all forms of conventional sterilisation. The risk of transmission of this agent is extremely low provided that scrupulous attention to detail is routinely employed in the decontamination process after every patient. In particular, all accessible endoscope channels should be brushed through with a single use purpose-made device or brush tipped wire assembly that has an appropriate length and diameter for each channel.

15. Any endoscopic procedure that breaches gut mucosa and is followed by the withdrawal of an unsheathed accessory through the working channel of an endoscope is deemed “invasive”. Procedures that cause tissue vaporisation (e.g. diathermy) are also deemed “invasive”. If an invasive procedure is undertaken in i) a patient with definite or probable vCJD, ii) a patient in whom a diagnosis of vCJD is being considered or iii) a patient at increased risk of vCJD (in whom infection should be presumed) through receipt of labile blood products, such as red cells from a donor who later developed vCJD, it will necessitate the subsequent quarantining of the endoscope used.

16. The performance of an “invasive” procedure (defined in it15 above) in a patient at risk of vCJD due to receipt of pooled plasma concentrates is no longer deemed to confer a high risk of endoscope contamination. A single quality assured decontamination cycle according to these guidelines is considered sufficient, but the endoscope should be decontaminated separately from other equipment within an EWD and with a single-use disinfectant. There is no longer a requirement to quarantine the endoscope provided that routine traceability data can demonstrate thorough reprocessing.

17. Single-use accessories should always be used. The choice of single-use biopsy forceps, guidewires and cytology brushes helps to minimise any possible risk of transmitting prion disease. Reusable accessories should be used only in situations where no single-use equivalent accessory exists, and they should be heat tolerant for sterilisation in the Sterile Services Department. Procedures should include a system for tracking use in each patient in these circumstances.

18. Rubber biopsy port caps must be discarded after all procedures involving the passage of biopsy forceps, guidewires and/or other accessories through the endoscope. Other detachable valves (primarily air/water and suction valves/pistons) should be manually cleaned according to the manufacturers’ instructions, then decontaminated with their corresponding endoscopes in an EWD, keeping the valves and endoscopes together as a traceable unique set. There is an increasing move towards using single-use endoscope valves to enable full traceability and to prevent cross infection caused by inadequate processing.

19. Due to the increase in demand for endoscopy, many units have had to expand in limited space, with the result that decontamination facilities have been moved to a location away from the endoscopy unit. Used endoscopes and their internal channels must be kept moist during transfer to decontamination facilities, and it is best practice that endoscopes are placed in an EWD within 3 hours of patient use. In addition, there must be electronic tracking of endoscopes between units and remote facilities.

20. By contrast, the channels of reprocessed endoscopes should ideally be dried prior to use in the next patient.

21. Control systems, like appropriate monitors, environmental testing, low level extraction and routine health screening, should be undertaken to minimise risks to staff Occupational health records should be retained for 30 years.

22. All staff involved in endoscopy and in endoscope decontamination should wear appropriate personal protective equipment (PPE) in line with local policy.

23. Out-of-hours endoscopy should not be performed unless there is an individual available who has been assessed as competent in pre-cleaning and manual cleaning processes. If the decontamination facility is remote from the endoscopy unit, it is best practice to be able to accept endoscopes for reprocessing every day of the week. A detailed risk procedure must be in place for this process.

24. Endoscopes used invasively, for example for Natural Orifice Transluminal Endoscopic Surgery (NOTES), and choledochoscopes should be manually cleaned, processed through an EWD and finally sterilised using a validated, compatible sterilisation process. High-level disinfection is not sufficient. Reusable sheathed accessories passed up the bile duct may also require sterilisation (see section 8 in the PDF).


Flexible endoscopes that enter normally sterile body cavities are regarded as “critical devices” and these flexible endoscopes must be decontaminated by manual cleaning, automated washing, and disinfection, followed by sterilisation using a process that is compatible with the endoscope. Examples of such endoscopes that may require sterilisation include choledochoscopes, those used for NOTES (natural orifice translumenal endoscopic surgery), cystoscopes, utereteroscopes and nephroscopes. This guidance is not intended for critical or high-risk devices, although the procedures for cleaning and disinfection prior to sterilisation do apply.


DOPS training and assessment tool for manual cleaning processes in endoscopic decontamination

Following collaboration between Olympus, Pentax and Aquilant, the BSG and the Decontamination Professional Expert Communication Forum (DPECF)  are pleased to announce the launch of this DOPS training and assessment tool.


There have been numerous reports on the potential transmission of multi resistant bacteria with particular reference to duodenoscopes and the manual cleaning of these instruments.

There is the potential to transmit infection via any endoscope through poor adherence to manual cleaning processes and to date there has been no single way of assessing and validating these processes. Knowledge and practice varies significantly between departments and indeed individuals and there is a need to have a standardised approach and pathway that can be quality assured and validated to minimise the risk to patients and staff from endoscopically transmitted infection.

Purpose and use

The purpose of this DOPs form is to provide a universal and standarised training and assessment tool for continuity when training in manual cleaning processes. It consists of two parts:

  • PART 1. Manufacturers will deliver the initial specific product training as they currently do, traceable to the product reprocessing instructions and confirming the topics covered in the training from the listed criteria (shaded grey on the DOPS form)
  • PART 2. The employer will then undertake an assessment of competency to undertake manual cleaning of endoscopes as part of the Skills for Health END21 competency and as annual revalidation of practice from the listed criteria on the form, including validation of competency in the topics covered in the manufacturer’s training.

Each section/topic should be signed and dated by the individual delivering the training or assessing the competency. This should then form part of annual appraisal and revalidation of practice.

Pentax DOPS form
Aquilant HC21 DOPS form - 19th May 2021
DOPs forms for use of endoscope washer disinfectors (EWDs)

Decontamination of medical devices standards and guidance for Scotland, Wales and Northern Ireland

Potential transmission of multi resistant bacteria and duodenoscopes


Simethicone Residue in Endoscopes

March 2017

Dr Helen Griffiths, Nurse Consultant & Decontamination Advisor British Society of Gastroenterology

A publication in 2016 in the American Journal of Infection control (Ofstead et al) outlined a potential risk following the identification of residual simethicone in endoscopes following the decontamination process in the United States.

At that time expert opinion in the UK concluded that the decontamination process was not well described and that bacteria found on processed scopes were suggestive of operator contamination and not compromised decontamination. Whilst not seen as a basis for modifying the use of simethicone at that time it has continued to be monitored.

Recently there has been an issue identified in the Republic of Ireland when a colonoscope was sent to Olympus for repair. Preliminary investigation showed what appeared to be signs of Simethicone residue ( Hypromellose, an ingredient of Infacol) in the auxiliary water channel of that colonoscope and subsequently a further two colonoscopes. At this time investigation is ongoing but evidence suggests that scopes were reprocessed in accordance with manufacturers instructions including use of MH-946 injection tube (octopus device).

Simethicone was administered via the flushing pump at a dilution of 25mls (40mgs/ml) in 2 litres of water.

There has been no evidence of resultant infection but until further investigation and testing on compatibility and following discussion with the Decontamination Professional Expert Communication Forum (DPECF) it is advised that Simethicone is administered either orally or via the biopsy port of endoscopes and NOT via either the water bottle or flushing pump devices. This will ensure that manual brushing of relevant channels can take place post procedure. The strength of the dilutent should also be kept to a minimum to achieve the desired effect.

Potential transmission of multi resistant bacteria and duodenoscopes

October 2015

Recent reports in the media have highlighted the potential for transmission of infection associated with duodenoscopes. A recent peer reviewed publication (Endoscopy (2015) 47: 493-502) described an outbreak of VIM-2 producing Pseudomonas aeruginosa and identified an issue with the design and reprocessing of a recently introduced duodenoscope with a specific modified design. This may be similar to the outbreaks in the US (Gastrointestinal Endoscopy (2015) 82(3): 477-83).

The BSG would like to highlight the following points to staff carrying out the decontamination of flexible endoscopes, in particular duodenoscopes:

  • Adherence to manufacturers’ instructions at all times is essential
  • The pre clean procedure should take place at the patient bedside, as described in the instructions from the UK suppliers and BSG guidance
  • The cover on the raiser bridge mechanism at the distal tip should be removed prior to brushing all areas of the distal tip and cleaning with detergent and replaced on completion of the decontamination process. The brush must be used on all surface areas of the distal tip ensure that all debris is removed
  • The elevator wire channel should be flushed with detergent during the manual cleaning ensuring the correct size syringe is used. If automated flushing systems are used for this stage of the process, staff should ensure that this channel is included.
  • Staff should ensure that the endoscope washer disinfector has the capability of flushing the elevator wire channel with detergent, disinfectant and rinse water
  • If stored in a drying cabinet, the elevator wire channel should be flushed with HEPA filtered air along with all the other channels. If this channel is not flushed with air, the endoscope should be used within 3 hours or the endoscope reprocessed before patient use. Not all cabinets have this facility. An EN standard, EN 16442, has now been published for endoscope storage drying cabinets
  • Routine microbiological surveillance of processed endoscopes is not recommended. However, this may be carried out on advice from the infection prevention and control team if an outbreak is known or suspected
  • Staff should receive comprehensive training, and a record retained, on all aspects of the decontamination of endoscopes, in particular, duodenoscopes

Choice Framework for Local Policy and Procedures CFPP 01-06

These documents offer best practice guidance on the management and decontamination of flexible endoscopes. They consist of five documents covering operational management, design and installation, testing methods, validation and verification and policy and management. These are large documents that will be subject to periodic updates and therefore it is recommended that rather than download all or part of the guidance the link is made available on endoscopy desktops. These guidelines are designed to provide information and guidance to those working within endoscopy services in England, please see the link below for relevant guidelines for Scotland, Wales and Northern Ireland.


Audit is key to understanding and ensuring that the decontamination environment and the processes within it are safe and effective. The MHRA (August 12) talks about the legal implications if there are failures in both understanding and practices in decontamination. The CFPP 0106 reminds us that the Health Act Code of Practice (2006) recommends that healthcare organisations comply with guidance establishing Essential Quality Requirements (EQR) and demonstrate that a plan is in place for progression to Best Practice (BP). There are a number of audit tools available for use within endoscopy to demonstrate compliance with EQR and allow planning to achieve BP. The Infection Prevention society has developed comprehensive audit tools to sit alongside the guidance in CFPP 01-06. These tools are now recommended by the member committees of the Professional Expert Communication Forum (PECF): Decontamination of medical devices as the UK wide audit tool of choice.

Access IPS audit tools here:

Access list of member organisations of the Professional Expert Communication Forum (PECF) here:

“Transmissible Spongiform Encephalopathy Agents: Safe Working and the Prevention of Infection”

As part of its remit for the whole of the UK the Department of Health ACDP TSE Risk Management Subgroup produces the guidance document Transmissible spongiform encephalopathy agents: safe working and the prevention of infection. The aim of the guidance is the minimisation of the risk of transmission of CJD, and vCJD. This has recently been reviewed by a working party of the subgroup and updated (February 2015) and it is recommended that decontamination teams review the changes to these documents.

Read the entire updated document on the Department of Health’s ‘Advisory Bodies’ website:

Read More

BSG logo
BSG, JAG, CSH Joint consensus on practical measures for environmental sustainability in endoscopy
This consensus on sustainable endoscopy was published in October 2022.

BSG logo
BSG guidelines on sedation in gastrointestinal endoscopy
This BSG guideline was published in September 2023.