Objective:To investigate the current application of colonoscopy at hospitals in China.Methods:From November 2019 to January 2020, an online questionnaire survey was conducted among gastroenterologists and colonoscopists in hospitals of different levels. The contents of questionnaire survey included basic information of colonoscopy at the respondent′s hospital, protocols and patient education of bowel preparation, implementation of colonoscopy quality control, and colonoscopists′ understanding of polypectomy techniques and post-polypectomy follow-up.Results:A total of 236 valid questionnaires were collected, involving 187 hospitals, and 143 (76.5%) had an annual operation capacity of more than 5 000 cases. In terms of bowel preparation, split-dosed polyethylene glycol electrolyte powder (PEG) was the most commonly used (60.4%, 113/187) and the most common volume of PEG was 3 L (67.4%, 126/187). Verbal (90.9%, 170/187) and written (79.7%, 149/187) instructions were given more often than other methods for patient education of bowel preparation. Antifoaming agent was routinely used in 124 (66.3%) hospitals. In terms of quality control, only 11.5% (20/174) hospitals implemented all four measures. In terms of polypectomy techniques, 98.1% (203/207) colonoscopists chose hot snare polypectomy or endoscopic mucosal resection for lesions of diameter>1 cm, while options varied for lesions of diameter<1 cm. The interval of follow-up after polypectomy recommended by colonoscopists was shorter than that by guidelines.Conclusion:Several problems are found in the survey in the application of colonoscopy in China, i. e., patient education of bowel preparation is not diversified; quality control of colonoscopy still needs to be strengthened; polypectomy techniques and follow-up after polypectomy need to be further standardized.

With the development of computer science and technology, artificial intelligence and big data have made key breakthroughs in various areas. The medical and health field has also been greatly affected. Although the diagnosis, treatment, monitoring and management of pancreatic diseases is relatively difficult, artificial intelligence and medical big data are being applied in these aspects and showing obvious advantages and potential for the application.

Objective:To explore the feasibility of estimating adenoma detection rate (ADR) based on polyp detection rate (PDR) in colonscopy.Methods:In the present single-center retrospective study, the conversion coefficient was calculated based on the total colonoscopy cases in 2017. ADR of each colonoscopists was estimated based on PDR and conversion coefficient, which was then verified compared with the actual ADR for consistency.Results:A total of 25 112 colonoscopies with 20 experienced colonoscopists were included. The overall conversion coefficient was 0.483. The intraclass correlation coefficient of the actual ADR and the estimated ADR was 0.818 (95% CI: 0.596-0.924, P<0.01). Conclusion:It is feasible to estimate ADR based on PDR, but this method is only an expediency. More attention should be paid to the establishment of a standardized electronic database.

Objective To evaluate the mid-to-long term therapeutic effect of endoscopic pneumatic dilation for achalasia of cardia (AC).Methods Endoscopic pneumatic dilation was used in 45 AC patients, with follow-up of 2-12 years. Eckardt score and Stooler grading were used before and after the operation for evaluation of curative effect of dilation. Results The operation success rate was 97. 8%( 44/45) and the effective remission rate was 93. 2%( 41/44 ). No massive hemorrhage, perforation or other serious complications occurred.The longest follow-up time was up to 144 months.Ten cases were followed up for over 60 months. Patients′symptoms relieved significantly (P＜0. 01). Eckardt scores in 24 months and 60 months after operation significantly decreased compared with those before the operation ( P＜0. 01). But Eckardt score in 60 months was higher than that in 24 months ( P＜0. 01). The length of the disease history was positively related to post-operative scores, and negatively related to efficacy ( P＜0. 01). Conclusion Endoscopic balloon dilation is a satisfactory therapy to AC with good efficacy and safety.

Objective To analyze the risk factors of delayed post-polypectomy bleeding ( DPPB) of colonoscopy. Methods The data of 459 patients who underwent colonoscopic polypectomy between January 2014 and May 2017 were summarized, and the risk factors of DPPB were analyzed. Results Among the 459 patients, a total of 572 polyps were removed, and DPPB occurred in 27 patients with 42 polyps. Univariate analysis revealed that gender (male 85. 2%), number of polyps removed (≥3 polyps, 59. 3%), complicated with hyperlipidemia (29. 6%), polyps′diameter (≥10 mm, 66. 7%), morphology (pedunculated, 81. 0%), pathological type ( adenoma, 95. 2%), and excision method ( endoscopic mucosal resection, 90. 5%) were significantly correlated with DPPB ( all P＜0. 05). Logistic regression analysis showed that gender, with hyperlipidemia, number of polyps removed, polyps′ size, and morphology were independent risk factors of DPPB (P＜0. 05). Conclusion The risk factors of DPPB include male, complicated with hyperlipidemia, excision of more than 3 polyps, more than 10 mm in diameter, and pedunculated morphology.

Objective:To establish an artificial intelligence (AI)-assisted colorectal polyps classification system (AI polyps system) by using clinical big data, and to conduct the clinical verification.Methods:From June 2018 to June 2019, the colonoscopy images of polyps from 16 participating research centers were prospectively collected. The basic information of the polyps (location, size, shape and pathological biopsy results) in colonoscopy images of colorectal polyps were marked by senior colonoscopist, and the outline of the polyp was circled for the development of the AI polyps system. Taking pathological biopsy results of polyps as the gold standard, the sensitivity, specificity, and positivity predictive value (PPV), negative predictive value (NPV) and accuracy of white light model, narrow band imaging (NBI) model, the combination of white light and NBI model and colonoscopists′ identification of polyps were calculated respectively. Paired McNemar test and Kappa test were used for statistical analysis. Results:A total of 15 441 qualified colonoscopy images were collected, including 9 109 images in white light model and 6 332 images in NBI model. At laboratory level, the sensitivity, specificity, PPV, NPV and accuracy of white light model and NBI model in the identification of the polyps were 90.3%, 98.3%, 89.8%, 98.4%, 97.2%, and 90.5%, 92.5%, 92.3%, 90.6%, 91.5%, respectively. In clinical verification phase, a total of 78 polyps of 56 patients with colorectal polyps were enrolled. The sensitivity, specificity, PPV, NPV and accuracy of the white light model and NBI model in the identification of polyps were 70.3%, 82.1%, 78.8%, 74.4%, 76.3%, and 78.4%, 87.2%, 85.3%, 81.0%, 82.9%, respectively. There were no statistically significant differences between the diagnostic results of colonoscopists, the white light model, the NBI model and the results of pathological results (all McNemar test, all P>0.05), but the consistency were general and the Kappa values were 0.632, 0.525 and 0.657, respectively (all P<0.01). The Kappa value of combination of the white light and NBI model and the pathological results was 0.575, however the consistency was general, but the difterence was statistically significant (McNemar test, P=0.004). Conclusions:The established AI polyps system has a certain role in assisting diagnosis, but the accuracy still needs to be improved.

Objective: To evaluate the clinical value of a commercial low-residue diet (LRD) for bowel preparation of colonoscopy. Methods: This study was a prospective, endoscopist-blind, and randomized controlled trial. Participants were randomly assigned to two groups according to administration of LRD: the experimental group and the control group. Bowel preparation quality, compliance and tolerability of the two groups were compared. Results: A total of 61 patients were enrolled, with 32 in the experimental group and 29 in the control group. The outcomes were as follows: Boston Bowel Preparation Scale (BBPS) (7.8±1.0 VS 7.1±1.3, P=0.037), the rate of bowel preparation adequacy (87.5% VS 79.3%, P=0.388), compliance rate of dietary restriction (78.1% VS 55.2%, P=0.057), preparation completion rate (93.8% VS 93.1%, P=0.919), cecal intubation rate (both were 100.0%) and cecum arrival time (9.1±2.9 min VS 9.8±3.7 min, P=0.417), incidence of adverse (3.1% VS 3.4%, P=0.944), and hunger rate before colonoscopy (34.4% VS 48.3%, P=0.102). Conclusion The LRD for bowel preparation of colonoscopy significantly improves BBPS, but its effect on improving the bowel preparation adequacy, patient compliance and tolerability needs to be confirmed by further larger-scale trials.