Colonoscopy in the patient requiring anticoagulation

Dis Colon Rectum. 2001 Dec;44(12):1845-8; discussion, 1848-9. doi: 10.1007/BF02234465.


Purpose: The aim of this study was to assess perioperative warfarin management and complications in patients requiring colonoscopy.

Methods: We retrospectively reviewed 109 cases of colonoscopies performed on 94 patients requiring anticoagulation with warfarin. Patients stopped their warfarin three days before colonoscopy. Coagulation profiles obtained just before the colonoscopy showed a median prothrombin time of 13.4 seconds with a range of 11.1 to 29.1 (normal range, 10.9-13) and a median international normalized ratio of 1.2 with a range of 0.9 to 2.6. Patients restarted warfarin the day after the examination.

Results: During the 109 colonoscopies, 47 percent of the patients underwent either hot biopsy or snare polypectomy. One examination that included several biopsies was associated with a hemorrhagic complication (0.92 percent) requiring hospitalization and transfusion. Subset analysis of the therapeutic (biopsy and snare polypectomy) group indicated a slightly higher complication rate (1.96 percent) with a median international normalized ratio of 1.3 (range, 1-2.3) and a median prothrombin time of 13.7 (range, 11.6-25.9).

Conclusion: Patients taking warfarin for anticoagulation may safely undergo colonoscopy. The risk of hemorrhagic complications increases slightly with hot biopsy or snare procedures. Further studies are needed to refine guidelines for colonoscopy in the patient requiring anticoagulation.

MeSH terms

  • Administration, Oral
  • Adult
  • Aged
  • Aged, 80 and over
  • Anticoagulants / administration & dosage*
  • Anticoagulants / adverse effects
  • Chi-Square Distribution
  • Colonoscopy* / methods
  • Female
  • Gastrointestinal Hemorrhage / etiology
  • Humans
  • International Normalized Ratio
  • Male
  • Middle Aged
  • Prothrombin Time
  • Retrospective Studies
  • Risk Factors
  • Safety
  • Treatment Outcome
  • Warfarin / administration & dosage*
  • Warfarin / adverse effects


  • Anticoagulants
  • Warfarin