Final answer:
Endoscopy procedure is the most reliable exam in diagnosing peptic ulcers.
Step-by-step explanation:
The nurse caring for a client with a suspected peptic ulcer would recognize endoscopy procedure as the most reliable exam in diagnosing the disease. Endoscopy allows for direct visualization of the stomach and duodenum with a camera, providing a definitive diagnosis of peptic ulcers. This procedure involves inserting a tiny camera through a tube called an endoscope to examine the upper gastrointestinal (GI) tract.