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Summary for secondary care

Bowel Cancer Screening: Guidelines for Colonoscopy in Secondary Care Settings


This specialist Guidelines summary covers guidance on colonoscopy for bowel cancer screening from Public Health England, including assessment, consent, procedure, and polyp removal. It is aimed at healthcare professionals working in secondary care settings and applies to England. For further information, including recommendations on governance, risk management, audit, quality standards, and patient information, refer to the full guideline.

Colonoscopy in the NHS Bowel Cancer Screening Programme

  • Colonoscopy should be offered to people within the bowel cancer screening programme (BCSP):
    • following a faecal immunochemical test (FIT) result requiring further investigation for assessment/polypectomy after abnormal computed tomography colonoscopy (CTC)
    • to check a polypectomy site of a BCSP patient post polypectomy
    • for surveillance of a BCSP patient post polypectomy
    • All people requiring a colonoscopy should be assessed for fitness by a specialist screening practitioner (SSP) prior to their procedure being booked
    • Bowel cancer screening patients should be assessed in a dedicated clinic. This consultation should take approximately 45 minutes per patient and fully prepare the individual for their procedure.

Patients Unfit for Colonoscopy

  • For people with significant comorbidities, the risks of colonoscopy may outweigh the benefits. In these situations, a clinical decision should be made in conjunction with the patient to discuss whether any screening intervention is appropriate
  • In cases where a patient is unfit for colonoscopy and the clinical condition will not improve, the patient can be ceased from screening. This should be documented after discussion with the patient, and episode notes entered onto the bowel cancer screening IT system (BCSS)
  • The clinician must also write to the screening hub to authorise the cease from the programme, documenting that it is with the patient’s consent. This documented evidence will be held on the person’s screening records
  • Some patients who are currently unfit for colonoscopy may have a condition that is likely to clinically improve, or be on medication such as anticoagulants that should not be stopped for a diagnostic procedure. In these situations, a clinical decision should be made following discussion with the patient on when and how to proceed
  • The options available in these circumstances include a CTC or to delay the colonoscopy
  • A subsequent plan for management of any pathology identified must be agreed with the patient in advance. These decisions should be documented and episode notes entered onto BCSS.


  • The consent process should be commenced in the SSP clinic or during the telephone consultation in the case of surveillance procedures
  • It is the responsibility of the SSP to ensure that the patient has understood enough information to be able to make an informed decision about whether to proceed with the investigation
  • The person may sign the consent form at the SSP appointment, subject to local policy
  • If the patient does not have the capacity to consent for the procedure, then a best interest meeting should be arranged by the screening centre to decide how to proceed
  • The consent process should follow the principles outlined in the British Society of Gastroenterology (BSG) guidelines on obtaining valid consent for gastrointestinal endoscopy procedures
  • The process must include:
    • what the test involves
    • benefits of the test
    • risks of the test
    • risks of not having the test
    • risks of sedation
    • potential to miss pathology
  • The consent form must be signed or confirmed by the patient and the accredited colonoscopist on the day of the procedure, prior to the patient entering the examination room
  • The accredited colonoscopist must ensure they reaffirm with the patient any medical conditions or medications that may have a bearing on the colonoscopy procedure
  • The accredited colonoscopist must ensure they are aware of any travel plans that the patient may have in the next 2 weeks and must have a discussion with the patient if this has an impact on the ability to perform a polypectomy
  • If polypectomy is not possible, then it is acceptable to perform a diagnostic examination with the patient’s consent and book another date when the patient can safely have their polypectomy procedure
  • During the colonoscopy procedure the patient has the right to withdraw consent at any time, and in this case the procedure must be stopped as soon as it is safe to do so. Some patients can continue with the procedure after a short pause, but consent to progress must be obtained from the patient
  • Patients should be made aware of any potential complications after the procedure, before being discharged from the endoscopy unit. They should also be given clear contact instructions for advice if it is required, along with what to do in an emergency
  • An arrangement should be made for an SSP to contact the patient within 24 working hours of the colonoscopy, to ensure no problems have occurred.

Colonoscopy Procedure

  • All BCSP colonoscopy procedures should be performed in a unit that has been awarded Joint Advisory Committee on Gastrointestinal Endoscopy (JAG) accreditation, and approved by the local screening quality assurance service (SQAS)
  • If a site loses JAG accreditation there is no requirement to stop screening while working towards re-accreditation, but commissioners and SQAS must be informed and provided with a recovery action plan
  • BCSP colonoscopy lists should be supported by two endoscopy nurses, at least one of whom is a registered nurse skilled in assisting with complex polypectomy and familiar with all the equipment
  • An SSP or screening practitioner should be in attendance to support the patient and record the outcome of the examination in real time on BCSS
  • The colonoscopist must be accredited by JAG to perform BCSP colonoscopy. Information about the application process and education material can be found on the Bowel Cancer Screener Accreditation website
  • Patients undergoing colonoscopy should be offered the following alternatives for analgesia:
    • nitrous oxide/oxygen (Entonox)
    • intravenous sedative or opioid medication
  • A small minority of patients may require intravenous propofol as deep sedation for colonoscopy and all centres should make a reasonable effort to provide this for appropriate patients. In cases where this is not possible, these colonoscopies can be performed by a BCSP-accredited colonoscopist on a symptomatic or theatre list. Alternatively, the patient may be transferred to another screening centre offering this service
  • In the case of an incomplete colonoscopy, it is at the discretion of the colonoscopist to request a repeat procedure, possibly by an alternative operator or with an alternative bowel preparation, or to request a BCSP CTC
  • If suboptimal views cannot be rectified by washing, a repeat colonoscopy or CTC should be arranged. It is not appropriate to shorten the surveillance interval for the patient in these circumstances.

Infection Control

  • All colonoscopy performed within the BCSP should comply with current national guidance on infection control and should be signed off by the local trust infection protection committee to ensure safe practice.

Removal of Polyps

  • The colonoscopist and all endoscopy staff must be familiar with all the endoscopic accessories, including the diathermy machine and its settings
  • Polyps should be removed safely using standard techniques. These include:
    • use of cold snare when appropriate
    • submucosal injection
    • consider closure of defects ≥2 cm, particularly in the right colon
  • Hot biopsy should not be used
  • In general, pedunculated polyps or sessile polyps <2 cm in size should be removed at the index colonoscopy. However, no colonoscopist should resect a polyp they consider to be beyond their level of expertise. Patient safety is paramount and, in these cases, the procedure should be rescheduled to be performed by a colonoscopist with the necessary experience
  • The management of large non-pedunculated colorectal polyps should be in line with BSG guidance
  • The polypectomy site, following resection of all lesions of 2 cm or larger, should be marked with a tattoo (apart from caecal and rectal locations where local policy may apply)
  • Sessile lesions that are removed without a histological R0 resection should be managed in accordance with the BSG surveillance guidelines
  • All screening centres should have one or more colonoscopists with the experience required to perform advanced polypectomy
  • If the resection of a polyp is beyond the expertise of local colonoscopists, for example, if it requires endoscopic submucosal dissection, this may be referred to another screening centre with the appropriate expertise. In these situations, a clearly documented pathway should be in place to show clinical responsibilities and timescales
  • Surgical resection for benign lesions should be avoided if possible but, when necessary, the outcome of surgery should be recorded and disseminated to facilitate learning
  • In cases where resection for a benign lesion is undertaken outside of the standard BCSP pathway, the outcome must be entered onto the BCSS to ensure the correct post polypectomy pathway is followed.

Post Polypectomy

  • Patients within the BCSP should have surveillance procedures performed at an interval determined by the BSG surveillance guidelines
  • Patients undergoing surveillance colonoscopy should be reassessed by an SSP prior to the procedure to ensure there is no new relevant medical information. This can be a telephone consultation, but they should be offered the opportunity of a face-to-face clinic meeting to discuss the procedure if they wish
  • All surveillance colonoscopy examinations should be performed within 3 months, and site check procedures should be performed within 6 weeks of the expected due date.

Colorectal Cancers

  • Screening centres should discuss any cancers that are identified within the screening centre at team meetings to incorporate any learning points from the discussions. Trust policies and processes for applying duty of candour must also be followed.