HP and duodenal ulcer: Considering the role of NSAID use in Hp negative DU cases, while the duodenal ulcer diagnosis was definitely associated with Hp infection in 84.9% of our cases whether as a single pathogenic factor (44.1%) or in combination with ASA and/or NSAIDs (40.8%), Hp negative but NSAID and/or ASA-positive ulcers were evident only in 9.2% of our patients.