Introduction

Gastric mucosal visibility is essential for high-quality upper gastrointestinal (GI) endoscopy. While simethicone and N-acetylcysteine (NAC) have been shown to improve mucosal visibility, the optimal time interval between preparation and endoscopy remains undefined.

Aims & Methods

This randomized controlled trial evaluated the effect of timing on mucosal visibility and explored the upper limit beyond which visibility begins to decline.
In this single-center, randomized controlled trial, adult patients undergoing elective upper GI endoscopy were randomized into four groups: placebo, simethicone + NAC with endoscopy performed after 10–20 minutes, 20–30 minutes, and >30 minutes. The primary outcome was the proportion of patients achieving adequate gastric mucosal visibility (GMV), defined as a score of <7 on a validated visibility scale. A pre-specified subgroup analysis of the >30 minute group was performed by stratifying patients into 20-minute intervals (31–50, 51–70, and 71–90 minutes) to assess the durability of mucosal clarity over time.

Results

Comparison	Adequate gastric mucosal visibility (%)	P
10–20 min vs 20–30 min	27% vs 62%	0.001
10–20 min vs >30 min	27% vs 67%	0.001
10–20 min vs Placebo	27% vs 2.6%	0.001
20–30 min vs >30 min	62% vs 67%	0.174
20–30 min vs Placebo	62% vs 2.6%	0.001

1,140 patients (median age 42years, 63.2% males) were included in the study. Adequate GMV was significantly higher in all preparation groups compared to placebo (p < 0.001). The 20–30 minute and >30 minute groups demonstrated the highest rates of adequate visibility (61.5% and 73.5%, respectively), both significantly superior to the 10–20 minute group (26.9%) and placebo (2.6%). In the >30 minute subgroup analysis, the 31–50 minute interval demonstrated the highest adequacy (73.5%). The 51–70 minute group showed moderate adequacy (52.1%), which was not significantly different from the 20–30 minute group (p = 0.207). However, the 71–90 minute group had reduced adequacy (43.8%) and did not differ significantly from the 10–20 minute group (p = 0.145). No adverse events were reported across study arms.

Conclusion

Endoscopy performed between 20 and 50 minutes after mucosal preparation yields optimal gastric mucosal visibility. A decline in visibility beyond 50 minutes suggests a practical upper limit for endoscopy timing following preparation. These findings support structured, time-sensitive scheduling following mucosal cleansing to enhance procedural quality.

Disclosure

None

Introduction

Underwater endoscopic mucosal resection (UEMR) has been increasingly utilized due to its clinical benefits. However, in patients with poor bowel preparation, UEMR is limited by impaired endoscopic visualization due to luminal turbidity. Viscoclear®, a gel designed to secure endoscopic fields, has been available in Japan since 2020 and has demonstrated a 92.2% effectiveness rate in improving visibility during bleeding or inadequate bowel prep. While its usefulness during UEMR has been anticipated, clinical evidence remains limited. We conducted an image analysis study to evaluate the visibility enhancement effect of gel immersion compared to underwater.

Aims & Methods

This study was a prospective randomized crossover trial to compare the endoscopic visibility of colorectal adenomatous lesions (6-20 mm) between under-water and under-gel observation. Each lesion was observed alternately in both settings using white light imaging (WLI), blue laser imaging (BLI), and linked color imaging (LCI). Color difference (ΔE) between tumor and adjacent non-tumor areas was calculated using the Lab color space in Photoshop (Adobe Systems Inc.) to evaluate lesion margins. Based on preliminary retrospective data from our institution, a sample size of 72 was calculated (power: 0.8, one-sided α: 0.05). (jRCTs062220033)

Results

Between July 2022 and May 2024, 72 lesions were enrolled. Median tumor size was 8 mm (range: 6–18 mm). Histopathology revealed 65 adenomas (90.3%), 2 cancers (2.6%), 3 traditional serrated adenomas (4.1%), and 2 hyperplastic polyps (2.8%). Boston Bowel Preparation Scale Segment Scores (BBPS-SS) were 3 in 50 cases, 2 in 21 cases, and 1 in 1 case.
Median ΔE values in the underwater group were 10.0 (WLI), 15.7 (BLI), and 11.7 (LCI), while those in the under-gel group were 12.4 (WLI), 21.1 (BLI), and 13.1 (LCI). ΔE was significantly higher in the under-gel group than the underwater group under WLI and BLI (p = 0.01 and p < 0.01, respectively).
In subgroup analysis by BBPS-SS, under-gel observation showed significantly higher ΔE in WLI and BLI when BBPS-SS ≤2 (p = 0.03 and p < 0.01, respectively). No significant differences were seen when BBPS-SS was 3.

Conclusion

Under-gel observation improved the visibility of lesion margins under WLI and BLI compared to underwater observation, particularly in patients with suboptimal bowel preparation. Gel immersion endoscopy may therefore be a useful adjunct in difficult visualization conditions during colorectal UEMR.

Introduction

Colon capsule endoscopy (CCE) or panenteric capsule endoscopy (PCE) offers a promising, non-invasive diagnostic approach for patients with iron deficiency anaemia (IDA). However, high rates of conversion to conventional colonoscopy (CCC) following capsule procedures reduce cost-effectiveness and patient satisfaction. Optimising the faecal immunochemical test (FIT) threshold may improve patient stratification and reduce unnecessary conversions in future applications within the IDA diagnostic pathway.

Aims & Methods

This study aimed to evaluate the accuracy of faecal immunochemical testing (FIT) in predicting colorectal cancer (CRC) and polyp burden in patients with iron deficiency anaemia (IDA), and to extrapolate these findings to assess FIT’s utility in predicting the likelihood of conversion from CCE to conventional colonoscopy (CCC) based on underlying pathology in IDA.
The CLEAR IDA study was a multicentre, retrospective observational study conducted across four UK hospitals. Data were collected over a six-month study period and included patients referred via the two-week-wait (2WW) cancer pathway for iron deficiency, with or without anaemia, over a 12-month timeframe. Colonoscopy findings were analysed and extrapolated using NHS England’s CCE-to-colonoscopy referral criteria to assess the predictive value of FIT for colorectal cancer (CRC), polyp burden, and CCC using ROC curve analysis. The optimal FIT threshold was identified through three complementary approaches: threshold-based analysis, decision curve analysis, and cost-benefit modelling.

Results

A total of 1,531 patients were analysed; only 1.6% underwent small bowel capsule endoscopy. The diagnostic accuracy (AUC) of FIT for predicting CRC, polypoidal lesions, and CCC was 0.78, 0.58, and 0.69, respectively. Threshold-based analysis identified FIT = 15 µg/g as the lowest level at which CCC rates significantly increased (p = 0.02; OR = 1.87; 95% CI: 1.07–3.14). Decision curve analysis showed maximum net benefit at FIT = 17.6 µg/g, while cost-benefit modelling identified 9 µg/g as the most cost-effective. An optimal cost-effective FIT threshold range was identified between 10 and 17.6 µg/g. Threshold selection should be tailored to local service capacity and resource availability.

Conclusion

Significant pathologies in the IDA pathway were uncommon. A FIT threshold range between 10–17 µg/g may enhance cost-effectiveness and guide appropriate PCE use in IDA.

References

1) Snook J, Bhala N, Beales ILP, et al. British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults. Gut. 2021 Nov;70(11):2030-2051.
2) (NICE) NIFHACE. PillCam COLON 2 for investigation of the colon through direct visualisation: NATIONAL INSTITUTE FOR HEALTH AND CARE EXCELLENCE; August 2024 [cited 2025 23/03/2025]; Diagnostics Assessment Programme]. Available from: https://www.nice.org.uk/guidance/gid-dg10083/documents/final-scope-2
3) Turvill J, Haritakis M, Pygall S, et al. Multicentre Study of 10,369 Symptomatic Patients Comparing the Diagnostic Accuracy of Colon Capsule Endoscopy, Colonoscopy and CT Colonography. Aliment Pharmacol Ther. 2025 Feb 26;0:1–13.
4) Cilona A, Zullo A, Hassan C, et al. Is faecal-immunochemical test useful in patients with iron deficiency anaemia and without overt bleeding? Dig Liver Dis. 2011 Dec;43(12):1022-4.
5) Turvill JL, Turnock D, Cottingham D, et al. The Fast Track FIT study: diagnostic accuracy of faecal immunochemical test for haemoglobin in patients with suspected colorectal cancer. Br J Gen Pract. 2021 Aug;71(709):e643-e651.

Introduction

Few studies have examined esophageal motility disorders in patients with type 2 diabetes operated with sleeve gastrectomy (SG) or gastric bypass (RYGB).

Aims & Methods

We have recently reported overall prevalence of gastroesophageal reflux disease (GERD) in this group of patients (1) and now aimed to investigate potential differences between the two surgical methods regarding the prevalence of dysmotility 5 years after surgery. Furthermore, we also aimed to analyse and report on the available GERD-data in detail.
In the Oseberg study (January 2013 – December 2022), 125 patients with BMI ≥ 35 kg/m² and type 2 diabetes were screened, sixteen patients were excluded or withdrew consent, leaving 109 patients allocated to SG (n=55) or RYGB (n=54). To assess reflux symptoms, GerdQ (Gastroesophageal reflux disease questionnaire) was completed. Gastroscopy and 24-hour pH monitoring were used to examine GERD. High-resolution manometry with the Chicago classification v3.0 was used to assess esophageal motility.

Results

At inclusion the average age was 47.7 years (SD 9.6), BMI was 42.3 kg/m2 (5.3), and 66% were women. At the 5-year follow-up, 29 (53%) patients in SG-group and 32 (59%) in RYGB-group underwent gastroscopy, 22 (40%) vs. 25 (46%) underwent 24-hour pH monitoring, 23 (42%) vs. 26 (48%) underwent manometry, and 42 (76%) vs. 42 (78%) completed GerdQ. The proportion of patients with GERD symptoms (GerdQ ≥8) was low in both groups, with a slightly lower prevalence after RYGB (2%) than after SG (14%). There was no difference in the prevalence of erosive esophagitis between the groups (38% in SG and 41% in RYGB), all findings with less advanced esophagitis (Los Angeles grades A and B), but one patient in each group had new onset Barrett's esophagus. The proportion of patients with pH<4 for more than 6% of the recording (Acid exposure time, AET) was significantly higher after SG compared with RYGB (59% versus 8%, p < 0.0001). Esophageal dysmotility was diagnosed in 14 (61%) after SG compared with 19 (73%) patients after RYGB. Most of these patients (n=22) had hypertensive or hypotensive lower esophageal sphincter (LES), with no difference between groups. The remaining 11 patients had ineffective esophageal motility (IEM) or elevated distal contractile integral (DCI). None of the patients with dysmotility reported swallowing difficulties or chest pain with food intake.

Conclusion

The Oseberg study demonstrates a high prevalence of asymptomatic esophageal dysmotility after SG or RYGB with uncertain clinical relevance. Furthermore, a seven times higher prevalence of pathological acid reflux after SG compared with RYGB was demonstrated, but the prevalences of erosive esophagitis and esophageal dysmotility were approximately similar between groups. Few of the examined patients reported GERD symptoms, hence objective assessment of GERD should be included in long-term follow-up after SG to detect and prevent the development of Barrett's esophagus, dysplasia, and adenocarcinoma.

References

1. Hauge JW et al., Effect of gastric bypass versus sleeve gastrectomy on the remission of type 2 diabetes, weight loss, and cardiovascular risk factors at 5 years (Oseberg): secondary outcomes of a single-centre, triple-blind, randomised controlled trial. Lancet Diabetes Endocrinol. 2025 Apr 1:S2213-8587(24)00396-6