Helicobacter pylori is a common infection linked to dyspepsia, peptic ulcer disease, and gastric cancer. The rapid urease test (RUT) is widely used for diagnosis, but its accuracy is influenced by proton pump inhibitor (PPI) use and site of gastric sampling. This study aimed to evaluate the effect of PPI use on RUT positivity, compare detection rates between corpus and incisura, and determine the incremental value of dual-site sampling.

We conducted a single-center observational study of 503 adult patients undergoing upper gastrointestinal endoscopy for dyspepsia. RUT was performed from the gastric corpus and incisura using identical kits. Clinical data, including PPI use, demographics, and symptoms, were recorded. Statistical analyses included Chi-square tests, McNemar’s test, Cohen’s kappa, and logistic regression.

Overall H. pylori prevalence by RUT was 25.4%. Positivity was 22.7% from corpus, 18.9% from incisura, and 25.4% when either site was positive. Corpus positivity was significantly higher than incisura (McNemar’s χ²=6.89, p=0.009). Dual-site sampling significantly increased detection compared to corpus alone (25.4% vs 22.7%, McNemar’s χ²=12.07, p=0.0005). If only corpus was sampled, 10.9% of positive cases would have been missed; if only incisura was sampled, 25.8% would have been missed. Agreement between corpus and incisura was good (κ=0.717). PPI use reduced incisura positivity (p=0.02) but not corpus (p=0.09). On subgroup analysis, the incremental benefit of dual-site sampling was more pronounced in PPI users (p=0.023). RUT positivity was associated with male gender (p=0.038) and younger age (p=0.046).

Dual-site RUT sampling improves detection of H. pylori, especially in patients on PPIs, and reduces false negatives compared with single-site testing. Corpus alone performs better than incisura, but dual-site testing should be considered in routine clinical practice to maximize diagnostic accuracy.