title: The role of aspirin in post-polypectomy bleeding--a retrospective survey.
abstract: BACKGROUND
  Bleeding following colonoscopic polypectomy is a common complication and has been reported to occur in up to 6.1% of patients. Several risk factors have been discussed but their overall contribution to post-polypectomy bleeding remains controversial. The aim of the study was to determine the rate of post polypectomy bleeding and to analyse the role of potential risk factors especially the role of aspirin.
  
  
  METHODS
  We conducted a retrospective cohort study of all patients who underwent polypectomy at Dunedin Hospital, New Zealand between January 2007 and June 2009.
  
  
  RESULTS
  During the study period, 514 patients underwent colonoscopy with polypectomy and a total of 1502 polyps were removed. From further analysis we excluded 21 patients; 15 patients had surgery immediately after colonoscopy for the diagnosis of colorectal carcinoma and 6 patients presented with symptoms of an acute lower gastrointestinal bleed prior to colonoscopy. Of the remaining 493 patients, 11 patients (2.2%) presented with post-polypectomy bleeding within 30 days of the investigation of which 8 were on aspirin. In total 145 patients were taking aspirin prior to colonoscopy and 348 patients were not taking aspirin. The use of aspirin was associated with an increased prevalence of post-polypectomy bleeding (OR=6.72, 95% C.I. 1.76 to 25.7). Interestingly, the use of non-steroidal anti-inflammatory drugs (NSAIDs) was not associated with risk of bleeding after polypectomy (OR=2.82, 95% C.I, 0.34 to 23.3).
  
  
  CONCLUSIONS
  Our study confirmed a significantly increased risk of lower gastrointestinal bleeding following polypectomy in patients taking aspirin. We would recommend approaching the patient on aspirin coming forward for a colonoscopy with potential polypectomy with caution.
authors.affiliation: Gastroenterology Unit, Southern District Health Board, Dunedin, New Zealand.
authors.forename: Antony
authors.initials: A
authors.lastname: Pan
authors.forename: Martin
authors.initials: M
authors.lastname: Schlup
authors.forename: Ralf
authors.initials: R
authors.lastname: Lubcke
authors.forename: Annie
authors.initials: A
authors.lastname: Chou
authors.forename: Michael
authors.initials: M
authors.lastname: Schultz
mesh_terms: D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects; D001241:Aspirin / Q000009:adverse effects*; D003108:Colonic Diseases / Q000139:chemically induced*; D003111:Colonic Polyps / Q000601:surgery*; D003113:Colonoscopy / Q000009:adverse effects; D016001:Confidence Intervals; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D010975:Platelet Aggregation Inhibitors; D001241:Aspirin