How is a rectoscopy performed?

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Last updated: April 3, 2026 • View editorial policy

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How to Perform Rectoscopy

Rectoscopy should begin with a digital rectal examination (DRE) in all cases to prepare the anal canal and assess for pathology, followed by scope insertion and systematic examination including rectal retroflexion in 90% of cases. 1

Pre-Procedure Preparation

Bowel Preparation

  • Enema preparation is standard for rectoscopy/flexible sigmoidoscopy
  • Sodium phosphate enemas are most commonly used 2
  • Combining enemas with oral laxatives (magnesium citrate or oral sodium phosphate) improves preparation quality 2
  • Caution: Avoid electrolyte disturbances and dehydration with oral osmotic agents 2
  • Aim for adequate preparation quality in at least 90% of cases (aspirational: 95%) 1

Anticoagulation Management

  • No need to stop anticoagulants or antiplatelet agents for rectoscopy/sigmoidoscopy as long as polypectomies are deferred to colonoscopy 2
  • Therapeutic warfarin increases bleeding risk after polypectomy but not biopsy 2

Technique of Insertion

Digital Rectal Examination (DRE)

  • Perform DRE in 100% of cases (or document omission) 1
  • Purpose: Prepares the anal canal for scope insertion and examines the anal canal and lower rectum for pathology 1
  • DRE is sensitive for detecting abnormalities in the lower rectum and upper anal canal 1

Scope Insertion

  • Goal: Examine as much of the distal colon as possible within scope length limits (typically 60-70 cm for flexible sigmoidoscopy) 2
  • The rectum is usually traversed by the distal 10-20 cm of the endoscope 2
  • Use carbon dioxide instead of air for insufflation - this reduces post-procedural discomfort and cautery-related complications 2

Insertion Depth Considerations

  • Document insertion depth in centimeters from the anal verge with a straightened endoscope 2
  • Rigid rectoscopy: Mean depth approximately 16 cm 3
  • Flexible rectoscopy: Mean depth approximately 33 cm, providing additional diagnostic information in 18.4% of patients 3
  • Insertion depths are typically less in women than men, possibly due to anatomical differences 2
  • Prior abdominal surgery or hysterectomy may limit insertion depth 2

Patient Comfort

  • Do not subject patients to excessive discomfort to achieve a predefined insertion depth 2
  • 80% of patients report flexible instruments cause no or only slight discomfort 3
  • Flexible instruments take slightly longer to reach maximal depth (mean 1 min 40 sec vs 1 min for rigid) 3

Examination Technique

Rectal Retroflexion

  • Perform retroflexion in 90% of cases 1
  • Retroflexion increases pathology detection by 2-8% beyond standard views 1
  • Success rates: 94-100% 1
  • Risk: Rectal injury is rare (estimated 0.01%) 1
  • Technique allows visualization of the lower rectum and upper anal canal that may be missed on forward view

Mucosal Examination

  • Ensure adequate colonic distension, suctioning, and cleaning 2
  • Spend adequate time examining the mucosa - correlates with higher detection rates 2
  • Document preparation quality and any impairment in confidence due to preparation 2

Biopsy Capability

  • Biopsies can be successfully taken under pneumorectum with modern digital rectoscopes 4
  • No increased bleeding risk with biopsy in anticoagulated patients 2

Documentation

Required Documentation

  • Record in 100% of cases: Whether DRE was performed or omitted 1
  • Insertion depth in centimeters from anal verge 2
  • Quality of bowel preparation 2, 1
  • Whether retroflexion was performed 1
  • Image/video capture for documentation and medicolegal purposes (with digital systems) 4

Common Pitfalls to Avoid

  1. Skipping DRE: This is a standard part of examination and should be documented in all cases 1
  2. Forcing insertion: Anatomical factors, preparation quality, or patient tolerance may limit depth - do not cause excessive discomfort 2
  3. Omitting retroflexion: This maneuver detects additional pathology in 2-8% of cases and should be attempted in 90% of examinations 1
  4. Using air instead of CO2: Carbon dioxide significantly reduces patient discomfort 2
  5. Inadequate preparation: 22% of failed procedures are due to poor bowel preparation 1

Modern Considerations

Digital rectoscopy systems now provide high-quality image capture, telemedicine capabilities, and improved ergonomics while maintaining low cost 4. These systems show 96% diagnostic accuracy with no adverse events in initial studies 4, and may facilitate training, proctoring, and remote consultation 5.

References

3
Research

[Rectoscopy: rigid or flexible? A comparative study].

Deutsche medizinische Wochenschrift (1946), 1985

4
Research

An Observational Analysis of a Novel Digital Rectoscope.

Diseases of the colon and rectum, 2021

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This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.