Peptic ulcer disease refers to open sores (ulcers) that can form in the stomach or first portion of the small intestine (duodenum). Most ulcers are caused by either a bacterial infection (H pylori) or by a group of anti-inflammatory medications known as NSAIDS (such as ibuprofen). Some ulcers cause no symptoms, while others can cause abdominal pain, nausea, vomiting, bleeding, or weight loss. Ulcers are most commonly diagnosed by an exam with a small camera (upper endoscopy, or EGD). Treatment is typical with acid-reducing medications known as proton pump inhibitors (PPIs) such as omeprazole (Prilosec), as well as antibiotics if an infection is present.