Incidence, Predictors, and Outcomes of Clinically Significant Post-ERCP Bleeding: a Contemporary Multi-center Study.

BACKGROUND AIMS: Clinically significant post-endoscopic retrograde cholangiopancreatography (ERCP) bleeding (CSPEB) is common. Contemporary estimates of risk are lacking. We aimed to identify risk factors for and outcomes following CSPEB. METHODS: We analyzed multi-center prospective ERCP data between 2018-2023 with 30-day follow-up. The primary outcome was CSPEB, defined as hematemesis, melena, or hematochezia resulting in: hemoglobin drop ≥20 g/L or transfusion and/or endoscopy to evaluate suspected bleeding, and/or unplanned healthcare visitation and/or prolongation of existing admission. Firth logistic regression was employed. P-values <0.05 were significant, with odds ratios (ORs) and 95% confidence intervals reported. RESULTS: CSPEB occurred following 129 (1.5%) of 8,517 ERCPs (mean onset 3.2 days), with 110 of 4,849 events (2.3%) occurring following higher-risk interventions (sphincterotomy, sphincteroplasty, pre-cut sphincterotomy, and/or needle-knife access). CSPEB patients required endoscopy and transfusion in 86.0% and 53.5% of cases, respectively, with three cases (2.3%) being fatal. P2Y12 inhibitors were held for a median of 4 days (IQR 4) prior to higher-risk ERCP. Following higher-risk interventions, P2Y12 inhibitors (OR 3.33, 1.26-7.74), warfarin (OR 8.54, 3.32-19.81), dabigatran (OR 13.40, 2.06-59.96), rivaroxaban (OR 7.42, 3.43-15.24) and apixaban (OR 4.16, 1.99-8.20) were associated with CSPEB. Significant intraprocedural bleeding post sphincterotomy (OR 2.32, 1.06-4.60), but not post sphincteroplasty, was also associated. Concomitant cardiorespiratory events occurred more frequently within 30 days following CSPEB (OR 12.71, 4.75-32.54). CONCLUSIONS: Risks of antiplatelet-related CSPEB may be underestimated by endoscopists based on observations of suboptimal holding before higher-risk ERCP. Appropriate periprocedural antithrombotic management is essential and could represent novel quality initiative targets.

Post-ERCP cholecystitis: Incidence, characteristics, and outcomes from a prospective multicenter biliary endoscopy registry.

BACKGROUND AND AIMS: The incidence, risk factors, and outcomes of post-ERCP cholecystitis are poorly described. We aimed to describe cases of post-ERCP cholecystitis from a prospective multicenter registry with protocolized 30-day follow-up. METHODS: Patient- and procedure-related data from 7 centers were obtained. The primary outcome was post-ERCP cholecystitis, defined according to a Delphi-based criteria and causal attribution system. Risk factors and outcomes were described for all cases. RESULTS: Seventeen cases of post-ERCP cholecystitis were identified among 4428 patients with gallbladders undergoing ERCP between 2018 and 2023 (incidence, 0.38%; 95% confidence interval, 0.20-0.57). In ERCPs with covered metal stenting, 7 of 467 resulted in cholecystitis (incidence, 1.50%; 95% confidence interval, 0.40-2.60). Patients had symptoms at a median of 5 days (interquartile range, 5) after ERCP. Management strategies included cholecystectomy, percutaneous cholecystostomy, and endoscopic stent removal/exchange. CONCLUSIONS: Estimates of post-ERCP cholecystitis incidence can inform discussions around procedural risk.

Comparison of Predictive Models for Prevention of Missed Endoscopy Appointments- failure of a Predictive Model to Outperform Overbooking Model.

BACKGROUND: Patient late cancelation and nonattendance for endoscopy appointments is an ongoing problem affecting the productivity and wait times of endoscopy units. Previous research evaluated a model for predictive overbooking and had promising results. STUDY: All endoscopy visits at an outpatient endoscopy unit during 4 nonconsecutive months were included in the data analysis. Patients who did not attend their appointment, or canceled with 48 hours of their appointment were considered nonattendees. Demographic, health, and prior visit behavior data was collected and the groups compared. RESULTS: 1780 patients attended 2331 visits in the study period. Comparing the attendee versus non-attendees, there were significant differences in mean age, prior absenteeism, prior cancelations, and total number of hospital visits. No significant differences were seen between groups in winter versus non-winter months, the day of the week, sex distribution, type of procedure booked, or whether the referral was from specialist clinic or direct to procedure. The visit cancelation proportion (calculated excluding current visit) was substantially higher in the absentee group ( P <0.0001). A predictive model was developed and compared to current booking as well as a straight overbooking of 7%. Both overbooking models performed better than the current practice, but the predictive overbooking model did not outperform straight overbooking. CONCLUSIONS: Developing an endoscopy unit specific predictive model may not be more beneficial than straight overbooking as calculated by missed appointment percentage.

Smartphone Application Versus Standard Instruction for Colonoscopic Preparation: A Randomized Controlled Trial.

OBJECTIVE: To compare smartphone application (Colonoscopic Preparation) instructions versus paper instructions for bowel preparation for colonoscopy. BACKGROUND: Adhering to bowel preparation instructions is important to ensure a high-quality colonoscopy. PATIENTS AND METHODS: This randomized controlled trial included individuals undergoing colonoscopy at a tertiary care hospital. Individuals were randomized (1:1) to receive instructions through a smartphone application or traditional paper instructions. The primary outcome was the quality of the bowel preparation as measured by the Boston Bowel Preparation Score. Secondary outcomes included cecal intubation and polyp detection. Patient satisfaction was assessed using a previously developed questionnaire. RESULTS: A total of 238 individuals were randomized (n = 119 in each group), with 202 available for the intention-to-treat analysis (N = 97 in the app group and 105 in the paper group). The groups had similar demographics, indications for colonoscopy, and type of bowel preparation. The primary outcome (Boston Bowel Preparation Score) demonstrated no difference between groups (Colonoscopic Preparation app mean: 7.26 vs paper mean: 7.28, P = 0.91). There was no difference in cecal intubation (P = 0.37), at least one polyp detected (P = 0.43), or the mean number of polyps removed (P = 0.11). A higher proportion strongly agreed or agreed that they would use the smartphone app compared with paper instructions (89.4% vs 70.1%, P = 0.001). CONCLUSIONS: Smartphone instructions performed similarly to traditional paper instructions for those willing to use the application. Local patient preferences need to be considered before making changes in the method of delivery of medical instructions.

Standardizing Scoring Conventions for Crohn's Disease Endoscopy: An International RAND/UCLA Appropriateness Study.

BACKGROUND AND AIMS: Endoscopic assessment of disease activity is integral for evaluating treatment response in patients with Crohn's disease (CD). We aimed to define appropriate items for evaluating endoscopic activity and conventions for consistent endoscopic scoring rules in CD. METHODS: A 2-round modified RAND/University of California at Los Angeles Appropriateness Method study was conducted. A panel of 15 gastroenterologists used a 9-point Likert scale to rate the appropriateness of statements pertaining to the Simple Endoscopic Score for CD, Crohn's Disease Endoscopic Index of Severity, and additional items relevant to endoscopy scoring in CD. Each statement was voted as appropriate, uncertain, or inappropriate based on the median panel rating and presence of disagreement. RESULTS: Panelists voted that it is appropriate for all ulcers to contribute to endoscopic scoring in CD, including aphthous ulcers, ulcerations at a surgical anastomosis, and anal canal ulcers (scored in the rectum). Endoscopic healing should reflect an absence of ulcers. Narrowing should be defined as a clear decrease in luminal diameter; stenosis should be defined by an impassable narrowing, and if occurring at the junction of 2 segments, scored in the distal segment. Scarring and inflammatory polyps were considered inappropriate for including in the affected area score. The optimal method for defining ulcer depth remains uncertain. CONCLUSIONS: We outlined scoring conventions for the Simple Endoscopic Score for CD and Crohn's Disease Endoscopic Index of Severity, noting that both scores have limitations. Therefore, we identified priorities for future research and steps for developing and validating a more representative endoscopic index in CD.

Existing Bowel Preparation Quality Scales Are Reliable in the Setting of Centralized Endoscopy Reading.

BACKGROUND: Development of bowel preparation products has been based upon colon cleansing rating by a local endoscopist. It is unclear how bowel preparation scales perform when centrally evaluated. AIMS: To evaluate the reliability of bowel preparation quality scales when assessed by central readers. METHODS: Four central readers evaluated 52 videos in triplicate, 2 weeks apart, during the entire endoscopic procedure (insertion/withdrawal of the colonoscope) and exclusively on colonoscope withdrawal using the Boston Bowel Preparation Scale (BBPS), Chicago Bowel Preparation scale, Harefield Cleansing Scale, Ottawa Bowel Preparation Quality Scale (OBPQS), Aronchick score, a visual analogue scale, and additional items proposed in a modified Research and Development/University of California Los Angeles appropriateness process. Reliability was assessed with intraclass correlation coefficients. RESULTS: Intraclass correlation coefficients (95% confidence interval) for inter-rater reliability of the quality scales ranged from 0.51 to 0.65 (consistent with moderate to substantial inter-rater reliability) during the entire procedure. Corresponding intraclass correlation coefficients for intra-rater reliability ranged from 0.69 to 0.77 (consistent with substantial intra-rater reliability). Reliability was highest in the right colon and lowest in the left colon. No differences were observed in reliability when assessed for the procedure overall (insertion/withdrawal) relative to assessment on withdrawal alone. CONCLUSION: All five bowel preparation quality scales had moderate to substantial inter-rater reliability. Panelists considered the Aronchick score too simplistic for clinical trials and recognized that assessment of residual fluid in the Ottawa Bowel Preparation Quality Scale was not amenable to central assessment.

Does Point-of-Care Ultrasound Change the Needle Insertion Location During Routine Bedside Paracentesis?

BACKGROUND: Paracentesis is a bedside procedure to obtain ascitic fluid from the peritoneum. Point-of-care ultrasound (POCUS) improves the safety of some medical procedures. However, the evidence supporting its utility in paracentesis is limited. OBJECTIVE: We aimed to assess if POCUS would yield a user-preferred site for needle insertion compared to conventional landmarking, defined as a ≥ 5 cm change in location. DESIGN: This was a prospective non-randomized trial comparing a POCUS-guided site to the conventional anatomic site in the same patient. PARTICIPANTS: Adult patients at Kingston Health Sciences Centre undergoing paracentesis were included. INTERVENTIONS: Physicians landmarked using conventional technique and compared this to a POCUS-guided site. The paracentesis was performed at whatever site was deemed optimal, if safe to do so. MAIN MEASURES: Data collected included the distance from the two sites, depth of fluid pockets, and anatomic considerations. KEY RESULTS: Forty-five procedures were performed among 30 patients and by 24 physicians, who were primarily in their PGY 1 and 2 years of training (33% and 31% respectively). Patients' ascites was mostly due to cirrhosis (84%) predominantly due to alcohol (47%) and NAFLD (34%). Users preferred the POCUS-guided site which resulted in a change in needle insertion ≥ 5 cm from the conventional anatomic site in 69% of cases. The average depth of fluid was greater at the POCUS site vs. the anatomic site (5.4±2.8 cm vs. 3.0±2.5 cm, p < 0.005). POCUS deflected the needle insertion site superiorly and laterally to the anatomic site. The POCUS site was chosen (1) to avoid adjacent organs, (2) to optimize the fluid pocket, and (3) due to abdominal wall considerations, such as pannus. Six cases landmarked anatomically were aborted when POCUS revealed inadequate ascites. CONCLUSIONS: POCUS changes the needle insertion site from the conventional anatomic site for most procedures, due to optimizing the fluid pocket and safety concerns, and helped avoid cases where an unsafe volume of ascites was present.

Prophylactic Endoscopic Clipping Does Not Prevent Delayed Postpolypectomy Bleeding in Routine Clinical Practice: A Propensity Score-Matched Cohort Study.

INTRODUCTION: Delayed postpolypectomy bleeding (DPPB) is a relatively common adverse event. Evidence is conflicting on the efficacy of prophylactic clipping to prevent DPPB, and real-world effectiveness data are lacking. We aimed to determine the effectiveness of prophylactic clipping in preventing DPPB in a large screening-related cohort. METHODS: We manually reviewed records of patients who underwent polypectomy from 2008 to 2014 at a screening facility. Endoscopist-, patient- and polyp-related data were collected. The primary outcome was DPPB within 30 days. All unplanned healthcare visits were reviewed; DPPB cases were adjudicated by committee using a criterion-based lexicon. Multivariable logistic regression was performed, yielding adjusted odds ratios (AORs) for the association between clipping and DPPB. Secondary analyses were performed on procedures where one polyp was removed, in addition to propensity score-matched and subgroup analyses. RESULTS: In total, 8,366 colonoscopies involving polypectomy were analyzed, yielding 95 DPPB events. Prophylactic clipping was not associated with reduced DPPB (AOR 1.27; 0.83-1.96). These findings were similar in the single-polyp cohort (n = 3,369, AOR 1.07; 0.50-2.31). In patients with one proximal polyp ≥20 mm removed, there was a nonsignificant AOR with clipping of 0.55 (0.10-2.66). Clipping was not associated with a protective benefit in the propensity score-matched or other subgroup analyses. DISCUSSION: In this large cohort study, prophylactic clipping was not associated with lower DPPB rates. Endoscopists should not routinely use prophylactic clipping in most patients. Additional effectiveness and cost-effectiveness studies are required in patients with proximal lesions ≥20 mm, in whom there may be a role for prophylactic clipping.

Reference letters for subspecialty medicine residency positions: are they valuable for decision-making? Results from a Canadian study.

BACKGROUND: The letter of recommendation is currently an integral part of applicant selection for residency programs. Internal medicine residents will spend much time and expense completing sub-specialty away electives to obtain a letter of recommendation. The purpose of this study was 1) to examine a large sample of reference letters in order to define essential components of a high-quality letter, and 2) to elucidate the relationship between quality of reference letter and the letter writer. METHODS: We conducted a two-phase study. In phase one, a large sample of letters of recommendation was examined using an audit tool as a coding framework. A 5-point composite endpoint of high-quality letter components was subsequently developed. In phase two, program director letters were compared to non-program director home institution and non-home institution elective letters based on inclusion of components of the 5-point composite endpoint using Chi square testing. RESULTS: 715 letters were examined (398 non-program director home institution letters, 201 program director letters, and 116 non-home institution elective letters). High-quality letter components were: nature of relationship, duration of relationship, In Training Evaluation Report information, research involvement and comments on areas for improvement. Program director letters had a significantly higher proportion (10.4%) of all 5 high-quality components, compared to 0% in both non-program director home institution letters and elective letters (p < 0.001). A significantly higher proportion of program director letters had 4-5 high-quality components (62.5%) compared to 2% of non-program director home institution letters and 0% of elective letters (p < 0.0001). CONCLUSIONS: Letters of recommendation from elective rotations are of the poorest quality and such rotations should not be pursued for the sole purpose of obtaining a letter. The low quality of elective letters leads to the recommendation that writers should decline to write them, programs should not require them and trainees should not request them. Program directors write the highest quality letters and should be a resource for faculty development. Clinical supervisors can use the 5-point composite endpoint as a guide when writing letters for applicants.

Anesthesia Assistance in Outpatient Colonoscopy and Risk of Aspiration Pneumonia, Bowel Perforation, and Splenic Injury.

BACKGROUND & AIMS: The increase in use of anesthesia assistance (AA) to achieve deep sedation with propofol during colonoscopy has significantly increased colonoscopy costs without evidence for increased quality and with possible harm. We investigated the effects of AA on colonoscopy complications, specifically bowel perforation, aspiration pneumonia, and splenic injury. METHODS: In a population-based cohort study using administrative databases, we studied adults in Ontario, Canada undergoing outpatient colonoscopy from 2005 through 2012. Patient, endoscopist, institution, and procedure factors were derived. The primary outcome was bowel perforation, defined using a validated algorithm. Secondary outcomes were splenic injury and aspiration pneumonia. Using a matched propensity score approach, we matched persons who had colonoscopy with AA (1:1) with those who did not. We used logistic regression models under a generalized estimating equations approach to explore the relationship between AA and outcomes. RESULTS: Data from 3,059,045 outpatient colonoscopies were analyzed; 862,817 of these included AA. After propensity matching, a cohort of 793,073 patients who had AA and 793,073 without AA was retained for analysis (51% female; 78% were age 50 years or older). Use of AA did not significantly increase risk of perforation (odds ratio [OR], 0.99; 95% confidence interval [CI], 0.84-1.16) or splenic injury (OR, 1.09; 95% CI, 0.62-1.90]. Use of AA was associated with an increased risk of aspiration pneumonia (OR, 1.63; 95% CI, 1.11-2.37). CONCLUSIONS: In a population-based cohort study, AA for outpatient colonoscopy was associated with a significantly increased risk of aspiration pneumonia, but not bowel perforation or splenic injury. Endoscopists should warn patients, especially those with respiratory compromise, of this risk.

Successful hemostasis of active lower GI bleeding using a hemostatic powder as monotherapy, combination therapy, or rescue therapy.

BACKGROUND AND AIMS: Acute lower GI bleeding is a frequent cause of hospital admission. The objective of this study was to evaluate the safety and performance of a hemostatic powder (TC-325/Hemospray) in the treatment of nonvariceal lower GI bleeding. METHODS: Patients were enrolled into this prospective, multicenter, single-arm study at 4 tertiary care centers in Canada. Fifty patients with active lower GI bleeding of multiple different causes (52 bleeding sites) underwent topical endoscopic application of hemostatic powder. The primary endpoint was powder-related adverse events within 30 days of the index procedure. Secondary endpoints were initial hemostasis as well as recurrent bleeding and mortality within 30 days of the index procedure. RESULTS: Most patients (96%) had a single bleeding site, and most bleeding (73%) was due to polypectomy. Overall, the powder was applied as monotherapy in 13 bleeding sites (25%), as combination therapy in 22 bleeding sites (42.3%), and as rescue therapy in 17 bleeding sites (32.7%). Hemostasis was achieved in 98% of patients. No patient experienced a powder-related adverse event. Five patients (10%) developed recurrent bleeding within 30 days. One patient (2%) died within 30 days of powder application, but the death was not directly related to hemostatic powder use. CONCLUSIONS: The hemostatic powder is a safe and effective option for patients with lower GI bleeding of varying causes, and in particular, postpolypectomy hemorrhage. The hemostatic powder is effective as monotherapy, part of a combination approach, or as a rescue therapeutic option for the treatment of nonvariceal lower GI bleeding. (Clinical trial registration number: NCT02099435.).

Peroral endoscopic myotomy (POEM) for complex achalasia and the POEM difficulty score.

BACKGROUND: Peroral endoscopic myotomy (POEM) for achalasia is technically challenging to carry out in patients with type III, multiple prior treatments, prior myotomy, and sigmoid type. Herein, we present a series of consecutive patients with complex achalasia and introduce the POEM difficulty score (PDS). AIM: To demonstrate the application and discuss the utility of PDS and present the feasibility, safety, and efficacy of POEM in complex achalasia patients. METHODS: Forty consecutive POEM were carried out with 28 meeting the criteria for complex achalasia. Primary outcome was clinical success (Eckardt score ≤3) at a minimum of 3 months follow-up. Secondary outcomes included adverse events, procedural velocity and PDS. RESULTS: Twenty-eight complex and 12 non-complex POEM procedures were carried out with 100% and 92% clinical success, respectively, without any major adverse events with a median follow up of 15 months (complex) and 8 months (non-complex). Mean velocities for non-complex, type III, prior myotomy, ≥4 procedures and sigmoid type were as follows: 4.4 ± 1.6, 4.8 ± 1.5, 5.9 ± 2.2, 6.9 ± 2.2 and 8.2 ± 3.2 min/cm, respectively. Median PDS for non-complex, type III, prior myotomy, ≥4 treatments and sigmoid type were 1 (0-3), 2 (0-4), 2.5 (1-6), 3 (2-6) and 3.5 (1-6), respectively. PDS was shown to correlate well with procedural velocity with a correlation coefficient of 0.772 (Spearman's P < 0.001). CONCLUSIONS: PDS identifies the factors that contribute to challenging POEM procedures and correlates well with procedural velocity. The order of increasing difficulty of POEM in complex achalasia appears to be type III, prior myotomy, ≥4 treatments and sigmoid type.

Clinical Practice Guidelines for the Use of Video Capsule Endoscopy.

BACKGROUND & AIMS: Video capsule endoscopy (CE) provides a noninvasive option to assess the small intestine, but its use with respect to endoscopic procedures and cross-sectional imaging varies widely. The aim of this consensus was to provide guidance on the appropriate use of CE in clinical practice. METHODS: A systematic literature search identified studies on the use of CE in patients with Crohn's disease, celiac disease, gastrointestinal bleeding, and anemia. The quality of evidence and strength of recommendations were rated using the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. RESULTS: The consensus includes 21 statements focused on the use of small-bowel CE and colon capsule endoscopy. CE was recommended for patients with suspected, known, or relapsed Crohn's disease when ileocolonoscopy and imaging studies were negative if it was imperative to know whether active Crohn's disease was present in the small bowel. It was not recommended in patients with chronic abdominal pain or diarrhea, in whom there was no evidence of abnormal biomarkers typically associated with Crohn's disease. CE was recommended to assess patients with celiac disease who have unexplained symptoms despite appropriate treatment, but not to make the diagnosis. In patients with overt gastrointestinal bleeding, and negative findings on esophagogastroduodenoscopy and colonoscopy, CE should be performed as soon as possible. CE was recommended only in selected patients with unexplained, mild, chronic iron-deficiency anemia. CE was suggested for surveillance in patients with polyposis syndromes or other small-bowel cancers, who required small-bowel studies. Colon capsule endoscopy should not be substituted routinely for colonoscopy. Patients should be made aware of the potential risks of CE including a failed procedure, capsule retention, or a missed lesion. Finally, standardized criteria for training and reporting in CE should be defined. CONCLUSIONS: CE generally should be considered a complementary test in patients with gastrointestinal bleeding, Crohn's disease, or celiac disease, who have had negative or inconclusive endoscopic or imaging studies.

Lack of benefit of active preparation compared with a clear fluid-only diet in small-bowel visualization for video capsule endoscopy: results of a randomized, blinded, controlled trial.

BACKGROUND AND AIMS: Controversy remains regarding the type and amount of precapsule bowel cleansing required for small-bowel video capsule endoscopy (VCE). This study aims to assess the efficacy and tolerance of 2 active preparations and a control group of clear fluids only. METHODS: Patients with clinical indications for VCE were randomized to (1) clear fluids only the evening before VCE, (2) 2 sachets of sodium picosulfate plus magnesium sulfate (P/MC) the evening before, or (3) 2 L of polyethylene glycol (PEG) the evening before. Diet instructions were the same for all 3 groups. Small-bowel cleansing was assessed in 3 ways: a 5-point ordinal scale (primary outcome), the percentage of time the small-bowel view was clear, and a validated computerized assessment of cleansing. RESULTS: In total, 198 patients were randomized and 175 patients completed the trial with a mean age of 49.2 years. There was no clear benefit of active preparation with either P/MC or PEG over clear fluids only in the overall 5-point rating scale or in the distal fourth of each examination. There was no difference in diagnostic yield between groups. Significant differences were seen concerning tolerance of the preparations, with a higher proportion rating it as easy or very easy in the clear fluids-only group (93%) and the P/MC group (67%) than in the PEG group (13%) (P < .0001). CONCLUSIONS: Small-bowel cleansing for VCE remains a controversial topic. This randomized control trial demonstrates no benefit in overall or distal small-bowel visualization with active preparation using either PEG or P/MC compared with clear fluids only. (Clinical trial registration number: NCT00677794.).

Risk factors for early colonoscopic perforation include non-gastroenterologist endoscopists: a multivariable analysis.

BACKGROUND & AIMS: Bowel perforation is a rare but serious complication of colonoscopy. Its prevalence is increasing with the rapidly growing volume of procedures performed. Although colonoscopies have been performed for decades, the risk factors for perforation are not completely understood. We investigated risk factors for perforation during colonoscopy by assessing variables that included sedation type and endoscopist specialty and level of training. METHODS: We performed a retrospective multivariate analysis of risk factors for early perforation (occurring at any point during the colonoscopy but recognized during or immediately after the procedure) in adult patients by using the Clinical Outcomes Research Initiative National Endoscopic Database. Risk factors were determined from published articles. Additional variables assessed included endoscopist specialty and years of experience, trainee involvement, and sedation with propofol. RESULTS: We identified 192 perforation events during 1,144,900 colonoscopies from 85 centers entered into the database from January 2000-March 2011. On multivariate analysis, increasing age, American Society of Anesthesia class, female sex, hospital setting, any therapy, and polyps >10 mm were significantly associated with increased risk of early perforation. Colonoscopies performed by surgeons and endoscopists of unknown specialty had higher rates of perforation than those performed by gastroenterologists (odds ratio, 2.00; 95% confidence interval, 1.30-3.08). Propofol sedation did not significantly affect risk for perforation. CONCLUSIONS: In addition to previously established risk factors, non-gastroenterologist specialty was found to affect risk for perforations detected during or immediately after colonoscopy. This finding could result from differences in volume and style of endoscopy training. Further investigation into these observed associations is warranted.