Introduction

The presence of bubbles during esophagogastroduodenoscopy (EGD) is common and may impair adequate mucosal visualization (MV).

Aims & Methods

The primary objective was to evaluate the effect of pre-endoscopic simethicone administration on mucosal visibility, using the GRACE (Gastroscopy Rate of Cleanliness Evaluation) scale. Secondary objectives included assessment of endoscopy duration, endoscopist satisfaction, and the detection rate of endoscopic findings.
This was a prospective, single-center, randomized, blinded study including patients undergoing elective EGD between December 2024 and March 2025. Patients were randomized into three groups: A (100 mg simethicone ≤10 minutes before EGD), B (100 mg simethicone >10 minutes before EGD), and C (50 mL water, placebo). All received a total volume of 50 mL. Patients with gastroparesis, achalasia, or prior gastrointestinal surgery were excluded. MV was assessed using the GRACE scale (validated in 2024), which scores each segment (esophagus, stomach, duodenum) from 0 to 3 based on bubble quantity, resulting in a total score from 0 (inadequate) to 9 (excellent). Endoscopist satisfaction was subjectively assessed on a scale from 0 (not satisfied) to 10 (highly satisfied).

Results

A total of 82 patients were included (18 in group A, 34 in group B, and 30 in group C). Fifty-two patients received 100 mg of simethicone and 30 received placebo. Median simethicone administration time was 8 minutes in group A and 19 minutes in group B. Simethicone significantly improved MV compared to placebo (mean GRACE score: 7.62±1.7 vs 5.83±1.7; p<0.001), with significant improvements in all segments (esophagus: 2.65 vs 2.03, p<0.001; stomach: 2.21 vs 1.63, p=0.002; duodenum: 2.69 vs 2.17, p=0.001). A very weak negative correlation was found between GRACE score and simethicone timing (r = -0.058; p = 0.685). Median endoscopist satisfaction was higher in the simethicone group (8 vs 7; p=0.001), and strongly correlated with total GRACE score (r = 0.855; p<0.001). No significant differences were observed in endoscopy duration (7 vs 6 minutes; p=0.800) or diagnostic yield (p=0.416).

Conclusion

Pre-endoscopic administration of simethicone significantly improved mucosal visibility across all upper GI segments, supporting its routine use in clinical practice. The GRACE scale is a useful and objective tool that correlates strongly with subjective endoscopist satisfaction.

References

Esposito G, Dilaghi E, Costa-Santos C, Ligato I, Annibale B, Dinis-Ribeiro M, Areia M; GRACE Investigators. The Gastroscopy RAte of Cleanliness Evaluation (GRACE) Scale: an international reliability and validation study. Endoscopy. 2025 Apr;57(4):312-320. doi: 10.1055/a-2422-0856. Epub 2024 Sep 25. Erratum in: Endoscopy. 2025 Apr;57(4):C2. doi: 10.1055/a-2545-0228. PMID: 39321961
Manfredi G, Bertè R, Iiritano E, Alicante S, Londoni C, Brambilla G, Romeo S, Menozzi F, Griffanti P, Brandi G, Moreschi O, Pezzilli R, Zullo A, Buscarini E. Premedication with simethicone and N-acetylcysteine for improving mucosal visibility during upper gastrointestinal endoscopy in a Western population. Endosc Int Open. 2021 Feb;9(2):E190-E194. doi: 10.1055/a-1315-0114. Epub 2021 Jan 25. PMID: 33532557; PMCID: PMC7834924.

Introduction

Artificial intelligence (AI) is playing an increasingly prominent role in gastrointestinal endoscopy, particularly in enhancing real-time lesion detection during colonoscopy. This study evaluates the impact of an advanced AI-assisted detection system on the Adenoma Detection Rate (ADR), Adenomas per Colonoscopy (APC), and predictive performance, comparing outcomes across endoscopists with different levels of experience.

Aims & Methods

Three endoscopists participated in the study: two with limited experience (Physicians A and B) and one expert (Physician C). A total of 720 colonoscopies were analyzed, with 400 procedures performed using AI assistance and 320 without, evenly distributed among the three operators.
Patients included were between 40 and 75 years of age and underwent colonoscopy either as a screening examination or following a positive fecal occult blood test. Exclusion criteria comprised a history of inflammatory bowel disease (IBD), hereditary polyposis syndromes, major colorectal surgery, or inadequate bowel preparation. For each procedure, data were collected on ADR, APC, the predictive accuracy of the AI system, and retraction time (from cecum to anus).

Results

The use of AI resulted in a marked and consistent improvement in all primary performance indicators across all three endoscopists.
In terms of ADR, Physician A improved from 23.8% without AI to 29.7% with AI; Physician B from 26.9% to 31.6%; and Physician C from 34.7% to 36.6%. Similarly, the APC index increased from 0.52 to 0.63 for Physician A, from 0.55 to 0.65 for Physician B, and from 0.64 to 0.73 for Physician C.
The AI system demonstrated high predictive accuracy across all operators, with no false positives recorded for polyps ≥4 mm in size. Prediction rates were 87.9% for Physician A, 89% for Physician B, and 92% for Physician C, confirming the device’s reliability in supporting polyp identification during real-time examination. Retraction times were slightly prolonged with AI usage: 8.3 minutes vs 7.5 for Physician A, 8.7 vs 7.4 for Physician B, and 8.8 vs 8.0 for Physician C. However, these differences did not reach statistical significance, indicating that AI support did not meaningfully affect procedural efficiency.

Conclusion

The integration of AI into colonoscopy workflows significantly improved both ADR and APC, with the most substantial impact observed in less experienced endoscopists. Physicians A and B, who initially showed suboptimal detection metrics, achieved levels of quality comparable to those of the expert operator in the absence of AI, highlighting AI’s value as a tool for bridging the gap in operator performance. The high predictive reliability of the system—particularly for clinically relevant lesions—and the absence of false positives ≥4 mm further support its clinical utility. Although retraction times increased slightly with AI, this change was not statistically significant, suggesting that the diagnostic advantages were not offset by decreased procedural efficiency. Overall, AI proves to be a valuable and scalable solution to enhance adenoma detection, support clinical training, and promote uniform quality standards in colorectal cancer screening.

References

1.Antonelli, G., Gkolfakis, P., Tziatzios, G., Papanikolaou, I. S., Triantafyllou, K., & Hassan, C. (2020). Artificial intelligence-aided colonoscopy: Recent developments and future perspectives. World journal of gastroenterology, 26(47), 7436–7443.
2.Hassan, C., Balsamo, G., Lorenzetti, R., Zullo, A., & Antonelli, G. (2022). Artificial Intelligence Allows Leaving-In-Situ Colorectal Polyps. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association, 20(11), 2505–2513.e4
3.Houwen, B. B. S. L., Hassan, C., Coupé, V. M. H., Greuter, M. J. E., Hazewinkel, Y., Vleugels, J. L. A., Antonelli, G., Bustamante-Balén, M., Coron, E., Cortas, G. A., Dinis-Ribeiro, M., Dobru, D. E., East, J. E., Iacucci, M., Jover, R., Kuvaev, R., Neumann, H., Pellisé, M., Puig, I., Rutter, M. D., … Dekker, E. (2022). Definition of competence standards for optical diagnosis of diminutive colorectal polyps: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement. Endoscopy, 54(1), 88–99.

Introduction

Inspection accuracy on colonoscopy is problematic because of the colon’s complex structure and the need for skillful operators. In particular, lesions in the ascending colon (AC) may be difficult to detect because of its high folds. Additionally, it has recently been reported that post-colonoscopy colorectal cancer is often located in the proximal colon. There are only a few reports on the effectiveness of retroflex inspection after forward view inspection in the AC during colonoscopy. While endoscopes and colonoscopy using artificial intelligence or image enhancement systems to detect lesions have been developed, it is important to reconsider basic endoscopic techniques, such as retroflex inspection, during colonoscopy.

Aims & Methods

We performed a prospective study to investigate the usefulness of retroflex inspection after forward view inspection in the AC during colonoscopy. Between August 2022 and December 2024, a single endoscopist enrolled and performed screening colonoscopies for 335 consecutive patients aged ≥40 years. Patients with inflammatory bowel disease, gastrointestinal polyposis, post-colorectal surgery, or poor preparation (≤1 point in at least one of three areas on the Boston Bowel Preparation Scale) were excluded from this study. The AC was inspected in this sequence: forward direction (Inspection 1), retroflex direction (Inspection 2), and forward direction (Inspection 3). The primary endpoint was the adenoma detection rate (ADR) in the AC. Secondary endpoints were the adenoma miss rate (AMR) in the AC per colonoscopy in Inspection 1 and Inspections 1+2, percentage of cases in which lesions were detected in Inspection 2, average observation time in the AC for each inspection, success rate of retroflexion in the AC, average pain score (0 points: no pain, 5 points: most severe pain), and complication rate during Inspection 2.

Results

We evaluated 300 patients with a median age of 66 years. The ADR in the AC for Inspection 1 vs. 1+2 was 18.7% vs. 28.7%, respectively (odds ratio: 1.749; 95% CI: 1.174–2.622; p = 0.005); the values for Inspection 1+2 vs. 1+2+3 were 28.7% vs. 30.0%, respectively (odds ratio: 1.066; 95% CI: 0.739–1.540; p = 0.788) (Table 1). The average AMR in the AC per colonoscopy for Inspection 1 vs. 1+2 was 12.6% (95% CI: 9.0%–16.2%) vs. 2.6% (95% CI: 0.8%–3.8%) (p < 0.001) (Table 1). The percentage of cases in which lesions were detected in Inspection 2 was 13.8% (41/298; total number of lesions: 47). The average diameter of lesions discovered and resected endoscopically during Inspection 2 was 6.1 mm (range: 3–20 mm). The locations of these lesions were as follows: proximal AC: 27.7% (13/47); mid-AC: 38.3% (18/47); and distal AC: 34.0% (16/47). The average observation times in the AC (Inspection 1 vs. 2 vs. 3) were 80.7 (95% CI: 77.8–83.6) vs. 59.1 (95% CI: 56.9–61.3) vs. 82.1 (95% CI: 79.4–84.8) seconds, respectively. The success rate of retroflexion in the AC was 99.3% (298/300), and the average pain score and complication rate during Inspection 2 were 0.5 points (95% CI: 0.4–0.6 points) and 0%, respectively.

Conclusion

Retroflex inspection following forward inspection in the AC during colonoscopy detects additional adenomas and is minimally invasive and safe. This technique contributes to improving the accuracy of colonoscopy.