Introduction

Colonoscopy techniques is an independent factor of adenoma detection rate. However, the colonoscope insertion methods and cecal intubation time is often ignored compared with relevant technology or colonoscopy performance indicator in withdrawal stage. The effect of water exchange (WE) method characterized by water infusion with water removal primarily during insertion stage on colonoscopy has remained controversial. We aimed to carry out a meta-analysis to systematically evaluate the relationship between WE and quality of colonoscopy compared with the conventional methods include air insufflation and carbon dioxide insufflation.

Aims & Methods

Aims: To evaluate the effect of water exchange method versus conventional methods including air insufflation and carbon dioxide insufflation method for the quality of colonoscopy.
Methods: ​We searched randomized controlled trials published up to October 2022 from PubMed, Web of Science, the Cochrane Library, CNKI, Wanfang, SinoMed databases. Two reviewers independently searched the literatures based on standards to extract the data and evaluate the quality. The primary outcomes were cecal intubation time and adenoma detection rate. The secondary outcomes included cecal intubation rate, quality of bowel preparation, pain score, number of abdominal compression, number of position change. Meta-analysis was conducted by RevMan5.4.1.The study protocol was registered in PROSPERO (CD42022327954).

Results

A total of 23 studies involving 10654 patients were included. Although cecal intubation time was prolonged in WE (MD=1.81, 95%CI: 1.28, 2.35; P < 0.001), WE had higher adenoma detection rate (OR=1.40，95%CI：1.26, 1.55；P<0.001), cecal intubation rate (OR=1.62；95%CI：1.24,2.10；P<0.001) and quality of bowel preparation (MD=0.61；95%CI：0.42, 0.79；P<0.001) compared with conventional colonoscopy. In addition, WE had significantly lower pain sores (MD=-1.07；95%CI：-1.39,-0.76；P<0.001), number of abdominal compression (OR=0.42；95%CI：0.29,0.60；P<0.001) and number of position change (OR=0.59；95%CI：0.42,0.82；P=0.002) than conventional colonoscopy.

Conclusion

Despite WE colonoscopy prolonged cecal intubation time, it could significantly increase adenoma detection rate, cecal intubation rate and quality of bowel preparation. And beyond that, WE reduced patient pain, the proportion of abdominal compression and position change. WE is a better choice for high-quality colonoscopy.

Introduction

Current colonoscopy quality indicators recommend a minimum withdrawal time (WT) of 6 minutes. However, this standard may reduce colonoscopy efficiency and does not account for endoscopists' experience or bowel preparation quality. This study aims to investigate whether the 6-minute WT remains necessary for experienced endoscopists with excellent bowel preparation (BBPS≥8) by comparing the impact of 5-minute versus 6-minute WT on adenoma detection rate (ADR) and adenoma miss rate (AMR).

Aims & Methods

This study based experienced endoscopists and excellent bowel preparation (Boston Bowel Preparation Scale score, BBPS≥8) is aimed to compare the effect of 5-minute WT versus 6-minute WT on adenoma detection rate (ADR) and adenoma miss rate (AMR).
This multicenter, randomized controlled trial involving 423 patients was conducted from June 2023 to March 2025 in 5 centers, including Wuxi People's Hospital, Jiangsu Province People's hospital, Xuzhou First People's Hospital, The Second Affiliated Hospital of Soochow University, Taizhou People's Hospital. Colonoscope was inserted and withdrew twice on each patient and all procedures for the same patient were done by the same endoscopist. Participants were randomly divided into the 5-minute WT group (the first WT-5-minute and the second WT-6-minute, n =214) and the 6-minute WT group (the first WT-6-minute and the second WT-6-minute, n=209), and a timer was used to adjust the withdrawal speed. The primary outcome was ADR and AMR.

Results

The baseline characteristics of the two groups were similar (Table 1) and colonoscopy characteristics of the patients in the two groups regarding quality of bowel preparation, cecal intubation rate, cecal intubation time, cecal intubation distance, number of abdominal compression, number of position change were comparable (Table 2). Overall ADR (39.7% vs 43.5%, P = 0.425), ADR in the first (36.0% vs 36.4%, P = 0.935) and second withdrawal (10.7% vs 13.9%; P = 0.327) were not significantly increased in the 6-minute WT group compared with the 5-minute WT group. Likewise, the overall advanced adenoma detection (AADR) (4.7% vs 5.3%, P = 0.780), AADR in the first (4.7% vs 5.3%, P = 0.780) and second withdrawal (0.5% vs 0.5%, P = 0.745) did not differ statistically. Further analysis showed that AMR (10.7% vs 13.9%, P = 0.372) was lower in the 5-minute WT group than in the 6-minute WT group, less adenomas were missed in the 5-minute WT group, although not statistically significant (Table 3).
Table 3. Lesion-level detection and miss rate in the two groups
PDR, polyp detection rate; ADR, adenoma detection rate; AADR, advanced adenoma detection rate; AMR, adenoma miss rate; AAMR, advanced adenoma miss rate; PMR, polyp miss rate.
Table 3. Lesion-level detection and miss rate in the two groups

Conclusion

Shortening WT from 6 to 5 minutes didn't reduce ADR based experienced endoscopists and excellent BBPS, a 5-minute WT benchmark was acceptable with experienced endoscopists and excellent bowel preparation quality of colonoscopy.

Introduction

Although current quality indicators of colonoscopy recommend 6 minutes as the minimum standard for withdrawal time (WT), long-term implementation of the 6-minute WT results in low colonoscopy turnaround efficiency and it don't take into account the effects of endoscopists experience and the quality of bowel preparation of colonoscopy .Whether it is still necessary to adhere to the 6-minute WT standard under the condition of experienced endoscopists and excellent bowel preparation quality is worthy of further discussion. Therefore, this study based experienced endoscopists and excellent bowel preparation (Boston Bowel Preparation Scale score, BBPS≥8) is aimed to compare the effects of 5-minute WT versus 6-minute WT on adenoma detection rate (ADR) and adenoma miss rate (AMR).

Aims & Methods

Aims：This study based experienced endoscopists and excellent bowel preparation (Boston Bowel Preparation Scale score, BBPS≥8) is aimed to compare the effect of 5-minute WT versus 6-minute WT on adenoma detection rate (ADR) and adenoma miss rate (AMR).
Methods：This multicenter, randomized controlled trial involving 298 patients was conducted from June 2023 to February 2024 in 5 centers, including Wuxi People's Hospital, Jiangsu Province People's hospital, Xuzhou First People's Hospital, The Second Affiliated Hospital of Soochow University, Taizhou People's Hospital. Colonoscope was inserted and withdrew twice on each patient and all procedures for the same patient were done by the same endoscopist. Participants were randomly divided into the 5-minute WT group (the first WT-5-minute and the second WT-6-minute, n =161) and the 6-minute WT group (the first WT-6-minute and the second WT-6-minute, n=137), and a timer was used to adjust the withdrawal speed. The primary outcome was ADR and AMR.

Results

The baseline characteristics of the two groups were similar (Table 1) and colonoscopy characteristics of the patients in the two groups regarding quality of bowel preparation, cecal intubation rate, cecal intubation time, cecal intubation distance, number of abdominal compression, number of position change were comparable (Table 2). Overall ADR(44.5% vs 41.6%, P = 0.613), ADR in the first (37.2% vs 36.6%, P = 0.918) and second withdrawal (15.3% vs 14.3%, P = 0.800) were not significantly increased in the 6-minute WT group compared with the 5-minute WT group. Likewise, the overall advanced adenoma detection (AADR) (8.0% vs 6.8%, P = 0.694), AADR in the first (7.3% vs 6.8%, P = 0.875) and second withdrawal (1.5% vs 0.6%, P = 0.888) did not differ statistically. Further analysis showed that AMR (23.5% vs 24.6%, P = 0.826) and advanced adenoma miss rate (AAMR) (6.7% vs13.3%, P = 0.543) were lower in the 5-minute WT group than in the 6-minute WT group, less adenomas and advanced adenomas were missed in the 5-minute WT group, although not statistically significant (Table 3).

Conclusion

Shortening WT from 6 to 5 minutes didn't reduce ADR based experienced endoscopists and excellent BBPS, a 5-minute WT benchmark was acceptable with experienced endoscopists and excellent bowel preparation quality of colonoscopy.

Disclosure

Conflicts of Interest: The authors declare no conflict of interest

Introduction

It remains unknown whether gastric histopathology is associated with the occurrence of colorectal diseases.

Aims & Methods

Aims：We aimed to clarify the association between gastric histopathology and colorectal diseases, especially colorectal polyps (CP). On this basis, we established risk prediction models for different colorectal diseases.
Methods: A retrospective cross-sectional study was conducted on 2540 patients who underwent gastroscopy and colonoscopy simultaneously in The Affiliated Wuxi People's Hospital of Nanjing Medical University from January 1, 2021 to August 31, 2023. Basic demographic data, previous medical history, clinical symptoms, important laboratory indicators, and gastric histopathology classification were collected for univariate and multivariate analysis. The nomogram model was constructed with R language while its calibration was tested by Hosmer-Lemeshow, its discrimination was evaluated by Area Under the ROC Curve (AUC), and its clinical efficacy was evaluated by Decision Curve Analysis (DCA).

Results

1: According to the results of colonoscopy, patients were divided into Normal group (N=601); Non-adenomatous polyp group (N=576); Adenomatous polyp group (N=1116); Inflammatory bowel disease group (N=149) and Colorectal cancer group (N=98). The average age of the five groups was (55.04±13.95) years, (58.74±11.58) years, (61.83±10.19) years, (50.48±16.64) years, and (66.10±10.80) years, respectively. The CRC group had the largest proportion of males, accounting for 59.2% (n=58).
2: The results of gastroscopy were divided into: Normal; NAG (non-atrophic gastritis); AG or IM (atrophic gastritis/intestinal metaplasia); Gastric polyps; Esophageal cancer; and SC-patho (pathological gastric cancer). The association between indicators and colonoscopy results was analyzed to establish risk prediction models for different colorectal diseases. We found that gastric histopathology was significantly correlated with NAP and AP; for clinical symptoms, abdominal pain was significantly correlated with colorectal diseases, and the contribution ranking was: NAP>IBD>CRC>AP; hematochezia was significantly correlated with IBD; for clinical indicators, anemia was significantly correlated with AP, and CEA was significantly correlated with CRC; for previous medical history, previous colonoscopy examination was significantly correlated with colorectal diseases, and the contribution ranking was: NAP>CRC>AP>IBD; history of hypertension and rheumatism disease were significantly correlated with NAP; history of chronic kidney disease and rheumatism disease were significantly correlated with AP; history of chronic kidney disease and gastrointestinal tumor were significantly correlated with CRC; history of hypertension and thyroid nodules were significantly correlated with IBD; for demographic indicators, age was significantly correlated with NAP, AP, and CRC; while BMI was significantly correlated with IDB.
3: Using R language to establish the nomogram prediction model, we could find that: all the prediction models had good discrimination, and the AUC of the CRC model reached 0.885. Through the calibration curve, we could find that all prediction models has strong consistency, among which the AP model has the highest consistency and the smallest absolute error value of 0.007.

Conclusion

The nomogram prediction model has good discrimination and calibration, and has good clinical value for predicting the occurrence probability of different colorectal diseases.

Introduction

The modality for colorectal cancer (CRC) screening has transferred from guaiac fecal occult blood testing (gFOBT) to fecal immunochemical testing (FIT), but its sensitivity remains lower. While total colonoscopy (TCS) has been anticipated as a new modality for CRC screening, conclusive results based on randomized controlled trials (RCTs) are still pending. Test performance RCTs have been utilized to predict the effectiveness of new modalities for CRC screening. They were adopted for the evaluation of cancer screening using a stepwise approach in the World Endoscopic Evaluation (Young et al. Cancer 2016).

Aims & Methods

A systematic review of test performance RCTs for CRC screening was conducted. Candidate articles were searched from inception to October 14, 2023, using Ovid MEDLINE, Cochrane Central Registry, Embase, and Ichushi-web. We compared the test performance of TCS screening, referring to the following modalities: gFOBT, FIT, flexible sigmoidoscopy (FS), and CT colonography (CTC). Single and multiple rounds were searched. Test performance indicators included participation rates in CRC screening, advanced neoplasia (AN) detection rates, and CRC detection rates. The primary results were evaluated using an intention-to-screen (ITS) based network meta-analysis, and a per-protocol analysis was also performed.

Results

Seventeen RCTs (13 from Europe, two from the US, and one each from Israel and China), involving a total of 341,123 healthy screening invitees, were included. The median participation rates for the programs based on FIT, FS, and TCS were 50.4 % (28.6-94.0%), 32.3% (7.9-52.1%), and 21.5% (10.0-42.5%), respectively. In the network meta-analysis, participation rates for TCS screening were significantly lower than the programs based on FS (RR=0.58; CI: 0.37-0.89), FIT (RR=0.45; CI: 0.31-0.65), and gFOBT (RR=0.45; CI: 0.30-0.69). Detection rates for AN were consistently higher for TCS than for FIT (RR= 2.18, 95%CI:1.46-3.26) but not statistically significant for FS (RR=1.06, 95CI: 0.65-1.73). Similarly, TCS had higher CRC detection rates compared to FIT (RR= 1.80, 95%CI:1.04-3.12) and FS (RR= 1.52, 95%CI:0.87-2.64). While AN and CRC detection rates for TCS were higher than those of CTC, the differences were not statistically significant (AN: RR= 1.02, 95%CI:0.65-1.73, CRC: RR= 0.73 95%CI: 0.32-1.64). The follow-up period of single-round RCTs was limited until diagnosis, but the screening frequency varied depending on the follow-up duration, which could affect effectiveness. Screening intervals were typically two years for FIT, five years for FS, and ten years for CS. One quasi-experimental study combined the following arms from different RCTs with extended follow-up: one-time CS, one-time FS, and four rounds of FIT (Grobbee et al. Clin Gastroenterol Hepatol 2020). The participation rate was higher for FIT (73%) compared to FS (31%) and CS (24%). Cumulative AN and CRC detection rates were higher for FIT (AN = 4.5%, 95%CI:4.2-4.9, CRC =0.5% 95%CI: 0.4–0.6), but nearly equivalent for CS (AN = 2.2%, 95%CI:1.8-2.6, CRC =0.2% 95%CI: 0.1–0.3) and FS (AN = 2.3%, 95%CI:2.0-2.7, CRC =0.2% 95%CI: 0.1–0.3).

Conclusion

The single-round test performance of colonoscopy screening might be superior to that of other modalities. To confirm the priority of TCS, it is insufficient to draw conclusions based on the results of a single-round performance, given variations in screening intervals and frequencies among other modalities. Cumulative effects among different modalities should be compared within the same follow-up period.

References

Young GP, Senore C, Mandel JS, et al. Recommendations for a step-wise comparative approach to the evaluation of new screening tests for colorectal cancer. Cancer. 2016;122(6):826-39.

Grobbee EJ, van der Vlugt M, van Vuuren AJ, et al. Diagnostic yield of one-time colonoscopy vs one-time flexible sigmoidoscopy vs multiple rounds of mailed fecal immunohistochemical tests in colorectal cancer screening. Clin Gastroenterol Hepatol. 2020;18(3):667-75.

Introduction

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related deaths globally, with increasing incidence and a trend toward younger patients. CRC develops through the adenoma-carcinoma sequence, typically over 10 to 15 years, offering a critical “golden window” for early diagnosis and intervention. Early prevention, diagnosis, and treatment are key to reducing CRC mortality, with high-quality colonoscopy playing a vital role. The adenoma detection rate (ADR), a key measure of colonoscopy quality, is influenced by factors such as withdrawal time, bowel preparation, physician experience, cecal intubation rate, and patient characteristics. This study aims to identify risk factors for colorectal adenoma and develop a risk prediction model to improve colonoscopy screening, enhancing adenoma detection rates and reducing CRC risk.

Aims & Methods

This study aims to investigate the risk factors for colorectal adenoma based on patient characteristics and factors related to the colonoscopy procedure, and to develop a risk prediction model for colorectal adenoma.
A retrospective study design was adopted, enrolling 830 patients who underwent painless colonoscopy at the outpatient clinic of the Affiliated Wuxi People's Hospital of Nanjing Medical University between January and June 2023. Data collected included patient characteristics such as gender, age, BMI, medical history, clinical symptoms, and personal history, as well as colonoscopy-related information such as the number, anatomical location, and histological type of adenomas, insertion time, withdrawal time, bowel preparation, and the physician's experience level. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors for colorectal adenoma. A nomogram risk prediction model for colorectal adenoma was constructed using R language, and its predictive performance was evaluated using ROC curves, calibration curves, and decision curves. Additionally, random forest (RF), XGBoost (eXtreme Gradient Boosting), and LightGBM (Light Gradient Boosting Machine) algorithms were applied to further validate the factors associated with the adenoma detection rate (ADR).

Results

Multivariate logistic regression analysis revealed the following independent risk factors for colorectal adenoma: age (OR = 1.05, 95% CI: 1.03–1.08, p < 0.001), male gender (OR = 1.79, 95% CI: 1.32–2.41, p = 0.005), physician experience level (OR = 1.79, 95% CI: 1.20–2.68, p = 0.005), and withdrawal time (OR = 1.00, 95% CI: 1.00–1.00, p < 0.001). The ROC curve for the risk prediction model of colorectal adenoma in the modeling cohort had an area under the curve (AUC) of 0.720, indicating good discriminative ability. The calibration curve showed good agreement between the predicted and observed values, and the decision curve analysis suggested that the model has high clinical predictive value. RF, XGBoost, and LightGBM algorithms also confirmed that age, gender, physician experience, and withdrawal time are important factors influencing ADR.

Conclusion

Male, older age, higher physician experience, and longer withdrawal time are independent risk factors for the occurrence of colorectal adenoma. This study established a risk prediction nomogram model for colorectal adenoma based on easily accessible clinical indicators, which can effectively guide colonoscopy screening, improve the detection rate of colorectal adenomas, and help reduce the incidence of colorectal cancer.

Introduction

There is a growing interest in the role of artificial intelligence in colonoscopy. In this systematic review and meta-analysis, we aimed to evaluate the efficacy of computer-aided detection (CADe) of colorectal adenomas and polyps.

Aims & Methods

We searched MEDLINE, EMBASE and CENTRAL (from inception to December 2022) for randomized controlled trials (RCTs) comparing colonoscopy with CADe versus standard colonoscopy (SC). We performed a random-effects meta-analysis and reported the results as relative risks (RR) or mean difference (MD) with 95% confidence intervals (CI).

Results

Twelve RCTs comprising 11,340 patients were included in the final analysis. The pooled adenoma detection rate (ADR) was significantly higher in the CADe group compared with the SC group (41.4% vs 33%; RR 1.26, 95% CI 1.18 – 1.35). CADe increased the detection of adenomas regardless of their size (≤5mm [RR 1.56, 95% CI 1.38 – 1.77], 6 – 9mm [RR 1.24 95% CI 1.05 – 1.47] and ≥10mm [RR 1.30, 95% CI 1.11 – 1.53]), location (proximal colon [RR 1.41, 95% CI 1.26 – 1.58] and distal colon [RR 1.44, 95% 1.29 – 1.61]) or morphology (polypoid [RR 1.35, 95% CI 1.17 – 1.56] and non-polypoid [RR 1.55, 95% 1.25 – 1.93]). There was no difference between the CADe and SC groups in detecting advanced adenomas or sessile serrated lesions. Colonoscopy withdrawal time was longer in the CADe group compared with the SC group (MD 0.34 minutes, 95% CI 0.17 – 0.51).

Conclusion

Using CADe during colonoscopy is associated with a significant increase in ADR and adenoma per colonoscopy, which was mainly due to the increased detection of diminutive adenomas. Long-term longitudinal studies are required to evaluate the effect of CADe on the risk of interval colorectal cancer and cancer-related deaths.