A type of ulcer is a PEPTIC ulcer, which is an open sore that develops in the lining of the stomach, small intestine, or esophagus. PEPTIC ulcers are caused by a combination of factors, including the bacterium Helicobacter pylori, certain medications, and stress. Symptoms of PEPTIC ulcers include abdominal pain, nausea, vomiting, and weight loss. Treatment for PEPTIC ulcers typically involves antibiotics, antacids, and lifestyle changes.