Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien–Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk.

A proportion of patients diagnosed with colorectal cancer have previously been investigated for gastrointestinal symptoms and survival appears reduced in these patients. Regular audit and analysis of previous investigations can identify common pitfalls in diagnosis, which should be used to inform training and improve practice.

Objective An important marker of colonoscopy quality is detection of pathology and incidence of missed pathology. Back-to-back colonoscopies cannot ethically be performed for quality assurance alone yet may be required for clinical reasons. This study aims to investigate the incidence of new findings in colonoscopies repeated within a 12 month period and considers the role of such an analysis in the assessment of colonoscopy quality. Design All colonoscopies performed over a 3-year period at an endoscopy training unit were studied. Colonoscopies repeated within a 12-month period were analysed. Results 5747 colonoscopies were performed over the study period. 137 repeat colonoscopies were included with median interval from initial colonoscopy of 174 days. 19 (14%) repeat colonoscopies yielded new findings including one cancer, 234 days following a normal colonoscopy. Additional polyps were identified in 13 colonoscopies indicating a missed polyp rate of 9%. In these, a median number of two polyps per colonoscopy with median size 5.5 mm were found. There was no morbidity associated with repeat colonoscopy in this series. New findings on repeat colonoscopy appeared more likely following initial colonoscopy by non-consultant non-training grade endoscopists (23% vs 11%, p=0.09) yet small numbers involved preclude meaningful comparison. Conclusions Analysis of clinically indicated repeat colonoscopies and rate of detection of new pathology may offer utility in colonoscopy quality assurance and would offer a direct assessment of the most important aspect of colonoscopy quality.

BSG abstracts Introduction C.difficile infection (CDI) is the most serious cause of hospital-acquired diarrhoea. Factors predicting outcome are unclear. We have assessed possible biomarkers of failure to respond to metronidazole in a prospective series of 43 inpatients with CDI. Methods At diagnosis (T 1) and after 3 days (T 2) of metronidazole 400mg tds po (n = 33) or 500mg tds iv (n = 10), we assessed haemoglobin, white cell count (WCC), platelet count, C-reactive protein (CRP), creatinine, albumin, pulse, BP, temperature, stool frequency and Bristol score. Cure was defined as formed stool on 2 consecutive days within 7 days of starting metronidazole; failure was clinical deterioration needing treatment with vancomycin, colectomy and/ or death within 28 days. Positive and negative predictive values (PPV, NPV) for failure of metronidazole were calculated. Results 17 patients failed metronidazole: 7 needed vancomycin and 10 died. Regardless of outcome, there were significant falls in CRP, pulse, stool frequency between T 1 and T 2 ; however, neither WCC and Bristol stool score did not fall in treatment failures (Table). The other measures did not change in either group (data not shown). PPV for treatment failure of increases in WCC and CRP (as separate variables) between T 1 and T 2 were 67% and 57%, with NPV 75% and 65% (accuracies 72% and 63%), respectively. However, PPV and NPV for treatment failure of increases in both WCC and CRP between T 1 and T 2 were 100% and 62% (accuracy 75%).

Conclusion Many colonoscopists appear willing to refer cases to a colleague for EMR, even if it involves transfer to another hospital. Evidence emerged for a small group of experts capable of handling very large polyps, yet referral for surgery remains common. A national referral network might reduce the rate of surgical intervention but while so many colonoscopists perceive themselves to be performing at the "cutting edge" support for this is likely to remain limited. Methods All patients undergoing BCSP colonoscopy over a 30-month period at our unit were identified and cross-referenced against colonoscopy records for the preceding 3 years. New diagnoses of colorectal cancer in the cohort were identified and cancer yield in those with and without recent colonoscopy compared using the chi-squared test. Results 1419 BCSP colonoscopies were performed in 1339 patients over the study period. 109 colonoscopies were repeats with median interval to repeat 378 days. Indication for prior colonoscopy included prior BCSP invitation (n = 90), polyp surveillance (n = 6) and symptoms (n = 13). There were 111 diagnoses of colorectal cancer in the cohort but no patient with a previous colonoscopy was found to have colorectal cancer. Cancer yield in first time BCSP colonoscopy was greater than in repeated colonoscopy (8% vs. 0% p = 0.002). Conclusion Cancer yield is reduced in BCSP patients with a recent negative colonoscopy. Excluding such patients would reduce pressure on endoscopy units and any morbidity associated with repeat colonoscopy. However, such an approach would be associated with a small risk of missed pathology. Larger studies are required to define the safety of this approach and inform national guidance.