The nurse is examining the chart of a client with a suspected duodenal ulcer. Which diagnostic exam best indicates a confirmation of the diagnosis? A. Elevated WBC count on laboratory results B. Gastric irritation indicated on upper GI C. A positive H. Pylori on endoscopic biopsy D. A positive hemocult stool specimen result

A duodenal ulcer is a type of peptic ulcer that occurs in the first part of the small intestine, also known as the duodenum. The primary cause of a duodenal ulcer is a bacterial infection caused by the Helicobacter pylori (H. pylori) bacterium. Although other factors such as long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) and excessive stomach acid secretion can contribute to the formation of a duodenal ulcer, the presence of H. pylori is the most common cause.

A. Elevated WBC count on laboratory results: An elevated white blood cell (WBC) count may suggest an infection, but it does not specifically indicate a duodenal ulcer. B. Gastric irritation indicated on upper GI: Gastric irritation can be an indicator of various gastrointestinal issues, including gastric ulcers and other disorders. It does not specifically confirm a duodenal ulcer. C. A positive H. pylori on endoscopic biopsy: A positive H. pylori result from an endoscopic biopsy strongly indicates a duodenal ulcer. An endoscopic biopsy can directly confirm the presence of the H. pylori bacteria, which is the most common cause of duodenal ulcers. D. A positive hemocult stool specimen result: A positive hemocult stool test indicates the presence of blood in the stool, which could be indicative of various gastrointestinal issues, including ulcers. However, the test doesn't specifically confirm a duodenal ulcer.

Based on the analysis of each option, the best diagnostic exam to confirm a duodenal ulcer is a positive H. pylori result from an endoscopic biopsy, as it directly links the presence of the H. pylori bacteria to the suspected ulcer site. Therefore, the correct answer is: C. A positive H. Pylori on endoscopic biopsy