Magnifying endoscopy combined with narrow-band imaging endoscopy is an emerging method for early gastric cancer screening and diagnosis However, its effectiveness is closely related to the cleaning quality of the gastric mucosal preparation. H. pylori infection is a major risk factor for inadequate gastric mucosa cleaning quality preparation. Multiple medications are useful in helping patients with gastric mucosal cleansing preparations. This randomized controlled trial study protocol aims to investigate the effect of different combinations of medications on the quality of gastric mucosal cleansing in an H. pylori-infected population.

This study is a prospective, randomized, single-blind, single-center trial. The subjects are patients who require magnifying endoscopy combined with narrow-band imaging and have evidence of H. pylori infection (a non-invasive diagnostic 13C urea breath test was used to examine the study subjects). These patients will be randomly assigned to the control group (Group A) and the experimental groups (Groups B, C, D, E, and F). Each group will consist of 44 patients, with a total of 264 patients expected to be enrolled. The core content of the drug preparation regimen for each group is as follows: Group A (control group) will take 10 ml of simethicone before the examination; Group B (experimental group) will take 20,000 units of pronase before the examination; Group C (experimental group) will take 600 mg of N-acetylcysteine before the examination; Group D (experimental group) will take 10 ml of simethicone +20,000 units of pronase before the examination; Group E (experimental group) will take 10 ml of simethicone + 600 mg of N-acetylcysteine before the examination; Group F (experimental group) will take 10 ml of simethicone + 20,000 units of pronase + 1 g of sodium bicarbonate before the examination. All group medications will be dissolved in 50 ml of warm water at 20-40°C. All patients will fast for ≥6 h and abstain from drinking for 2 h before the examination. The primary endpoint is the gastric mucosa cleanliness score. Secondary endpoints include the early detection rate of gastric cancer, polyp detection rate, adenoma detection rate, procedure time, number of irrigations, patient medication compliance, preoperative anxiety, incidence of adverse reactions, overall patient satisfaction, and willingness to undergo the examination again.

The results of this research project are aimed at improving the quality of gastric mucosal cleansing preparations in the H. pylori population to meet the demand for early diagnosis and treatment prevention screening for early gastric cancer screening. The implementation of the results of the study and their inclusion in the guidelines may reduce economic expenditures by reflecting a reduced need for social and health care services.

Chinese Clinical Trial Registry (ChiCTR). Number of identification: (ChiCTR2400087510).

CT colonography (CTC) has demonstrated equivalent accuracy to optical colonoscopy in the detection of clinically relevant polyps and tumors but this is only possible when technique is optimized. The two most important features of a high-quality CTC are a well-prepared colon and a distended colon. This article will discuss the dietary, bowel preparation, and fecal/fluid tagging options to best prepare the colon. Strategies to optimally distend the colon will also be discussed. CT scan techniques including patient positioning and radiation dose optimization will be reviewed. With proper technique which includes sufficient bowel preparation, fecal/fluid tagging, bowel distension, and optimized scan technique, high-quality CTC examinations should become more feasible, easier to interpret, and more consistently reproducible leading to increased utilization and increased referrals.

We aimed to compare iohexol vs. diatrizoate as fecal/fluid tagging agents for computed tomography colonography (CTC) regarding examination quality.

Forty prospective patients (M:F = 23:17; 63 ± 11.6 years) received CTC using 50 mL (350 mgI/mL) oral iohexol for tagging. Forty other indication-matched, age-matched, and sex-matched patients who underwent CTC using 100 mL diatrizoate for tagging and otherwise the same technique, were retrospectively identified. Two groups were compared regarding overall examination quality, per-patient and per-segment scores of colonic bubbles (0 [no bubbles] to 5 [the largest amount]), and the volume, attenuation, and homogeneity (untagged, layered, and homogeneous) of the residual colonic fluid.

The iohexol group demonstrated a greater amount of colonic bubbles than the diatrizoate group: mean per-patient scores ± SD of 1.2 ± 0.8 vs. 0.7 ± 0.6, respectively (p = 0.003); and rates of segments showing ≥ grade 3 bubbles of 12.9 % (85/659) vs. 1.6 % (11/695), respectively (p = 0.001). Residual colonic fluid amount standardized to the colonic volume did not significantly differ: 7.2 % ± 4.2 vs. 7.8 % ± 3.7, respectively (p = 0.544). Tagged fluid attenuation was mostly comparable between groups and the fluid was homogeneously tagged in 98.7 % (224/227) vs. 99.5 % (218/219) segments, respectively (p = 0.344). Iohexol caused more colonic bubbles when used during cathartic CTC. Otherwise, examination quality was similarly adequate with both iohexol and diatrizoate.

• When used for tagging, iohexol caused significantly more colonic bubbles than diatrizoate. • The residual colonic fluid amount did not significantly differ between iohexol and diatrizoate. • The quality of fluid tagging was similarly adequate in both iohexol and diatrizoate.