Peptic ulcers come with a lot of misconceptions. Commonly referred to as ulcers or stomach ulcers, they can occur in your stomach, esophagus, or duodenum (upper part of your small intestine). Well-meaning people may tell you that your stressful job caused the ulcer, or that you should avoid eating spicy foods. However, these statements are not true. Much more is known about ulcers today than ever before.