Peptic ulcers are sores that form in the lining of the stomach, or the duodenum, the first part of your small intestine. The most common symptom of stomach ulcers is burning stomach pain. The pain may come and go for a few days or weeks, and often gets worse on an empty stomach and gets better after eating. Stomach ulcers need to be treated or they will get worse. Treatment may include medications, lifestyle modifications, and surgery. Follow the links below to find WebMD's comprehensive coverage about how you get stomach ulcers, what they look like, how to treat them, and much more.